Poisons and Toxins
Chemicals, Drugs, and other Toxins
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The first aid section covers what basic steps should be taken if you suspect your pet has been poisoned. The basic steps in helping your pet should always include:
1. Remove substance and prevent any further contact or exposure.
2. Thoroughly flush skin or eyes with large quantities of water. Wear gloves while
handling the animal to prevent contact with
offending or dangerous substance.
3. Provide plenty of fresh air for the the cat to breathe.
4. Induce emesis (vomiting) unless a.) it has been over 2 hours since the suspected poison was ingested or b.) if the cat is very depressed or unconscious, or c.) if you suspect the animal of having ingested a petroleum product, acids, alkali, tranquilizers or other drugs, which cause vomiting.
Emesis can be induced by giving the cat a tablespoon of syrup of ipecac (less to small cats), OR a tablespoon of hydrogen peroxide. The ipecac is the most reliable emetic drug.
5. Allow the cat to drink fresh water unless it is vomiting.
6. Bring the pet to a veterinary care center quickly, and try to bring a sample of the vomit, and/or any boxes or cans which you suspect the toxins may have come in.
For specific, detailed information contact a Poison Control Center. A Poison Reference has also been included below to help match the specific poisoning to the exact chemical(s) responsible and move you directly to the appropriate section. Read carefully any labels or information available on the material(s) you believe poisoned your pet. This information will speed your search herein and be important to your veterinarian as well.
ACETAMINOPHEN AND PHENACETIN
Sources Many prescription and over-the-counter brands of analgesic and antipyretic
drugs contain acetaminophen or its ethyl ether, phenacetin. Examples are Tylenol,
SineAid, SineOff, Anacin-3, Comtrex,
Daytril, Nyquil, Allerest, and Vanquish.
Mechanism of action Phenacetin is metabolized to acetaminophen.
Acetammophen is metabolized by enzymes of the cytochrome P-450 series to intermediate
products: nonreactive glucuronides and sulfates (which are conjugated and eliminated in
the urine), and reactive metabolites, which are metabolized with glutathione to nontoxic
mercapturic acid (which is eliminated). If the toxic metabolites accumulate as a result of
insufficient glucuronide or sulfate metabolism or insufficient glutathione, they are
converted to toxic macromolecules that directly cause cellular death. Cats lack glucuronyl
transferase and inefficiently form glucuronic acid and sulfate conjugates, leaving more
acetaminophen or phenacetin to be metabolized to toxic metabolites. The glutathione stores
are rapidly depleted in cats, leaving a large amount of toxic metabolites.
Methemoglobinernia occurs.
Clinical signs Acute signs in cats are related to methemoglobin
formation, whereas acute signs in the dog are related to hepatic damage. Toxicity is
mainly seen in cats when even a small amount of acetarninophen is
ingested (half of a 325 mg tablet for a 3.5 kg cat); dogs can usually tolerate dosages up
to 100 mg/kg. Signs include cyanosis (which is caused by methemoglobinemia), dyspnea,
facial edema (a hallmark of acetaminophen poisoning mechanism unknown), depression,
hypothermia, vomiting. Signs may progress to weakness, coma, and subsequently death.
Increased ALT from hepatic damage may be seen.
Treatment Since the toxic metabolites bind preferentially with
glutathione rather than cell macromolecules, supplying a glutathione precursor is an
important part of treatment. N-Acetylcysteine provides the cysteine needed for glutathione
synthesis and also increases serum sulfate levels, which supplies sulfate for conjugation.
Ascorbic acid is used to change methemoglobin to reduced hemoglobin. Acetarninophen is
rapidly absorbed and reaches peak blood levels within 30 to 60 minutes; emesis is
performed immediately after ingestion (if possible), and a saline cathartic is given.
Steroids should not be given because they have been reported to cause a dose-dependent
increase in mortality. Antihistamines have been reported to be contraindicated.
Signs
Cyanosis
Dyspnea
Facial edema
Depression
Hypothermia
Vomiting
Increased ALT
Weakness
Coma
Death
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood for laboratory testing.
Administer fluids as needed to support blood pressure and
perfusion.
4. Control seizures.
Decontaminate
I . Induce emesis if sate to do so or perform gastric lavage .
2. Administer activated charcoal. Repeat dose every 3 to 4 hours. If
N-acetylcysteine is to be given orally, activated
charcoal administration should be delayed for 30 to
60 minutes.
3. Administer saline or osmotic cathartics.
Administer antidotes or other indicated supportive care
1. N-Acetylcysteine (Mucomyst) 280 mg/kg PO loading dose (dogs) or 140 to 240 mg/kg
PO loading dose (cats), followed
by 140 mg/kg PO q4h for 3 days (dogs) or 70 mg/kg q6h for 3 days
of treatments (cats). Mucomyst, although not labeled
for IV use, can be administered intravenously (either directly
from the bottle or diluted in D 5W) by infusion through a 0.2
pin filter. The oral route is preferred because Mucomyst is
rapidly absorbed from the GI tract where it enters the portal
circulation. This is believed to increase the amount of drug
presented to the liver, the site of utilization.
2. Administer fluids to maintain hydration and urine output.
3. Treat increased intracranial pressure if suspected.
4. Ascorbic acid at 30 mg/kg PO, SC, or 20 mg/kg IV may be given as an attempt to
convert methemoglobin to
oxyhemoglobin If severe acidosis (pH <7. 1, rare), sodium
bicarbonate can be used. Cimetidine reduces metabolism of
acetaminophen by the cytochrome P-450 system. Metabolism of
acetaminophen by this system results in the production
of a hepatotoxic metabolite. Therefore the administration of
cimetidine is warranted.
Enhancement of elimination
Hemoperfusion has been shown to enhance elimination of acetaminophen.
Avoid
Excessive handling and stress.
References
Aronson LR, Drobatz KJ Acetaminophen toxicosis in 17 cats, J Vet Emerg Crit Care
6(2):65-69, 1996. Cullison R: Acetarninophen toxicosis in small animals: clinical signs,
mode of action, and treatment, Compend Cont Ed Pract Vet 6(4):315-320, 1984.
Hjelle J: Acetaminophen-induced toxicosis in dogs and cats, J Am Vet Med Assoc
188(7):742-745, 1986.
0ehme F: Aspirin and acetaminophen. In Kirk RW, editor: Current veterinary therapy,
Philadelphia, 1986, Saunders.
ACETONE (Organic Solvents and Fuels)
Sources This section includes many chemicals that are found in
solvents, degreasing agents, dry cleaning agents, and fuels for camp stoves, warmers, etc.
Acetone, benzene, benzol, methanol,
methylene chloride, naphtha, trichloroethane,
trichloroethylene, toluene, toluol, xylene,
and xylol are examples included in this category.
Mechanism of action Nearly all these compounds cause pulmonary
injury from direct effects with inhalation or systemic effects from ingestion and
inhalation. Pulmonary aspiration is one of the greatest concerns in patients exposed to
these compounds. Aspiration of very small amounts will likely induce chemical pneumonia.
Most of these agents also have direct CNS-depressant effects. They are reported to be
irritating to the skin, eyes, and mucous membranes. Further, they are known to sensitize
the myocardiurn to catecholamines, thus increasing cardiac dysrhythmias. Hypoxemia may be
seen if the patient was exposed to the compound in an enclosed space. Hepatic and renal
injury may occur by undefined mechanisms.
Signs Inhalation or exposure to fumes causes conjunctivitis, nausea,
vomiting, depression, wheezing, cyanosis, weak pulse, convulsions, and collapse. Signs
noted after ingestion include nausea, vomiting, diarrhea (hemorrhagic at times), fixed
pupils, ataxia, depression, and coma. Hemolysis and methemoglobinemia have been reorted
with exposure to naphthalene and toluene.
Treatment Treating poisoning by inhalation requires removing the patient
from the source, administering oxygen (when available), and washing the eyes copiously
with water. Treating poisoning by ingestion involves oxygen therapy, treatment for
aspiration or chemical pneumonia (see discussions of bronchospasm, and pulmonary edema,
cautious gastric lavage, activated charcoal, and a cathartic. Epinephrine and other
catecholamines should be avoided if possible because of the possible sensitization of the
myocardium by these agents.
Signs
| INHALATION Conjunctivitis Nausea Vomiting Depression Cyanosis Weak pulse Convulsions Collapse |
INGESTION Nausea Vomiting Diarrhea (possibly bloody) Fixed pupils Ataxia Depression Methemoblobinemia Hemolysis . Coma |
EMERGENCY TREATMENT
Procedures
I Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure
and perfusion.
5. Control seizures.
6. Treat bronchospasm, pulmonary edema, methemoglobin.
Decontaminate
If exposure is by inhalation, remove the source or move the patient to a well-ventilated
environment. Do not induce emesis. Perform cautious gastric lavage if the ingestion was
within the last I to 2 hours. Take care not to allow aspiration of gastric contents during
procedure. Give activated charcoal. Administer saline or sorbitol cathartic.
Magnesium-containing solutions should be avoided.
If exposure is dermal, bathe the patient in warm, soapy water or mild dishwashing
detergent (Dawn) and rinse well with warm water. Perform this in a well-ventilated room.
Avoid inducing hypothermia.
Administer antidotes or other indicated supportive care
1. There are no known antidotes.
2. Treat chemical pneumonia with oxygen, ventilation, nebulization, and
coupage ('percussion of the thorax to aid in the
removal of secretions). Broad-spectrum antibiotics are not
indicated prophylactically but may become necessary if the
chemical pneumonia initiates bacterial infection. Monitor
blood counts, sputum, and pulmonary washings as necessary to
determine the need for antibiotics.
3. Monitor ECG and treat cardiac dysrhythmias. CAUTION:
These agents cause increased myocardial sensitivity. Use of
epinephrine or other sympathomimetic amines may
induce or aggravate cardiac dysrhythmias.
4. Monitor urine output and renal parameters to observe for onset of
acute renal failure.
5. Monitor for evidence of hepatic injury and treat accordingly.
6. Treat methemoglobinernia if present.
Enhancement of elimination
There are no techniques that are effective.
Avoid
Catecholamines
References
Kirk RW, Bistner SI, Ford RB: Handbook of veterinary procedures and emergency treatment,
ed 5, Philadelphia, 1990, Saunders.
Osweiler GD, Carson TL, Buck WB, Van Gelder GA: Clinical and diagnostic veterinary
toxicology, ed 3, Dubuque, Iowa, 1985, Kendall/Hunt.
Sources Household cleaning products, toilet bowl and drain cleaners,
dishwasher detergents, cleaners, antirust compounds, alkaline batteries.
Mechanism of action Acids produce corrosive burns, resulting in
coagulation necrosis, which limits their penetration into deeper tissues. Visible lesions
(necrotic eschars) are seen on mucous membranes; laryngeal spasm and edema may occur.
Alkalis produce liquefaction necrosis, allowing deep tissue penetration that continues
until the alkali is neutralized by the tissues.
Clinical signs Irritation of the oral mucous membranes is
prominent; ptyalism is common. Oral ulcers and burns may be present but, when absent, do
not indicate a lack of esophageal involvement. Gray, yellow, or..black lesions most
commonly result from acids. Pain, vocaCization, dysphagia, panting, laryngeal edema with
upper airway obstruction, abdominal pain, hematemesis, and shock have been reported. In
cases of severe injury, perforation of the esophagus or stomach (especially in the region
of the pylorus) may be seen. Signs include ptyalism, pain, pneumothorax, peritonitis,
pleuritis, sepsis, shock, collapse, and death.
Treatment
GENERAL
Emesis and lavage are contraindicated. Activated charcoal is ineffective. Both acids and
alkalis can induce pain upon exposure to mucous membranes; this usually limits the amount
of concentrated poison ingested, which minimizes esophageal injury. Diluted agents produce
less pain and potentially more severe esophageal burns. injury to the pharynx, larynx, or
glottis may cause loss of airway requiring immediate endotracheal tube placement or
tracheostomy tube placement.
In general, caustic substances such as acids or alkalis cause local injury, mostly to the
mouth, esophagus, and stomach. The degree of oral injury does not correlate well with
deeper injuries. For this reason, endoscopic examination of the esophagus and stomach is
indicated in patients who have ingested a caustic substance. The procedure should be
performed 12 to 24 hours after the incident based on clinical signs.
Treatment of ingestions usually is limited to administration of diluents such as water or
milk. Systemic supportive measures must be instituted on a case-by-case basis. Some
patients will require intensive shock therapy, whereas others may require only minimal
treatment for oral burns.
Pain control is almost always indicated. Corticosteroids may minimize scar formation and
thus limit the degree of stricture in cases of esophageal burns. They should be started
within 48 hours of injury. Broad-spectrum antibiotics are indicated when steroid therapy
is used.
ALKALI INGESTION
Emesis and lavage are contraindicated in alkali ingestion. Gastric secretions are usually
sufficient to neutralize the alkali. Activated charcoal is ineffective in alkali
ingestion. Since the clinical signs rarely correlate to the degree of esophageal or
gastric injury, endoscopic exam should be performed in patients with alkali burns. The
procedure should be delayed until the patient has been evaluated for at least 12 hours,
and then the procedure should be performed carefully. The procedure should be halted at
the first sign of esophageal necrosis.
Ingested alkaline batteries should be removed from the esophagus endoscopically as soon as
possible to prevent perforation. If the battery is in the stomach, the probability of
perforation is greatly reduced, but the battery should be retrieved in a timely manner.
Consider induction of emesis, whole bowel irrigation, or endoscopic retrieval. Serial
radiographs to monitor the position of the battery are indicated.
ACID INGESTION
When acids contact mucous membranes, intense pain results. For this reason, most animals
will not ingest very much. Emesis is contraindicated. The patient should be given copious
quantities of diluents such as water or milk. Activated charcoal is ineffective.
Supportive care is advised. With severe esophageal injury, food and water are withheld
until endoscopic evidence of healing is available; the animal is maintained on parenteral
food and water or with a feeding tube (as with a jejunostomy, gastrostomy).
TOPICAL EXPOSURE
Topical exposure to acids or alkalis should be treated with extensive irrigation with
running water. The area should be flushed for at least 30 minutes. If the eye was exposed,
it should be flushed with water or saline (strongly advise sterile saline if available)
for 30 minutes.
Signs
Irritation of oral mucous membranes
Salivation
Oral ulcers or burns
Oral lesions colored gray, yellow, or black (acids)
Hematemesis
Panting, dyspnea (especially upper airway although pulmonary edema has been reported)
Pain
Vocalization
Dysphagia
Shock
Perforation of the esophagus (stomach or intestines may perforate but are less likely to
do so)
Pneumothorax
Peritonitis
Pleuritis
Sepsis
Shock, collapse, and death
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer large volumes of water (preferable) or milk orally.
Decontaminate
1. GI exposure (ingestion). Emesis and gastric lavage are
contraindicated in alkali and acid injuries. Rarely the use of gastric
lavage with aluminum hydroxide at 30 to 90
mg/kg for acid injury if esophageal injury is minimal has been recommended.
2. Dermal exposure. Wash thoroughly with warm water (with or without
soap) for a minimum of 30 minutes. Wear rubber
gloves when bathing the patient; avoid inducing
hypothermia.
3. Exposure of the eyes. Flush the eyes with water or sterile saline
(preferable) for 30 minutes.
4. Administer crystalloid fluids to maintain blood pressure or hydration
and urine output.
Enhancement of elimination
There are no known effective techniques
Avoid
Do riot give "neutralizing agents." These are usually heat-producing reactions,
which may cause additional injury.
ISOPROPANOL (ISOPROPYL ALCOHOL)
Sources Isopropanol (2-propanol, secondary propyl alcohol,
dimethylcarbinol and petrohol) is used as an antiseptic and disinfectant and in skin
lotions, hair tonics, after-shave lotions, perfumes and colognes, cleaning solvents, and
sanitizers.
Mechanism of action Isopropanol is a potent CNS depressant. It is
twice as toxic as ethanol; intoxication can be seen after ingestion of less than 3.0
mL/kg. It is a gastrointestinal irritant when ingested. Isopropanol is readily absorbed
from the GI tract; the rate of biotransformation is generally slower than that for
ethanol. Inhalation can produce chemical pneumonia, pulmonary edema, and coma.
Clinical signs The pet will appear drunk and often has an alcohol
odor. Emesis, including hematemesis, retching, and cranial abdominal tenderness may be
seen. Rapid CNS depression characterized by respiratory depression and coma occur. CNS
stimulation may be observed preceding the depression if the product contains camphor,
methyl salicylates, or naphthalenes. Shock can occur, as can ketonemia with uria (usually
without glucosuria) and high anion-gap acidosis. Signs are similar to methanol, ethanol,
and ethylene glycol intoxication.
Treatment Although gastric lavage will probably not remove
much isopropanol from the gut (because of alcohol's rapid absorption from the stomach),
lavage is advised if large amounts were ingested within the past 2 hours. Emesis is not
recommended because of the potential for rapid onset of CNS depression, which increases
risk of aspiration. Dialysis is used in people.
Signs
Drunkenness
Alcohol odor
Emesis, hematemesis
Retching
Cranial abdominal tenderness
CNS depression (may follow CNS stimulation)
Respiratory depression
Coma
Shock
Ketonemia, ketonuria
High anion-gap acidosis
Increased osmolar gap
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for
laboratory testing.
Decontaminate
INGESTION
1. Perform gastric lavage if large ingestions within
the past 2 hours.
2. Although isopropanol is not adsorbed well by
activated charcoal, current literature recommends activated charcoal be
administered.
3. Administer saline or osmotic cathartic. Cathartics
containing magnesium should be avoided because of the potential for
additional CNS depression from magnesium.
Administer antidotes and other supportive care
1. There are no known antidotes.
2. Blood gas determinations are important. CNS
depression may induce respiratory acidosis. lsopropanol induces a wide
anion-gap metabolic acidosis as well. The combination
may cause profound acidernia.
3. Administer crystalloid or colloid fluids to support
blood pressure, hydration, and urine output as needed.
Enhancement of elimination
1. Hemodialysis is helpful in removing the alcohol from the body, though
this is rarely necessary because most patients can
be treated successfully with supportive care alone.
2. Peritoneal dialysis is effective, but, because most patients can be
treated successfully with supportive care alone, it is
not likely to be worth the risks associated with it.
3. Heinoperfusion, inultiple-dose activated charcoal, and forced
diuresis are not helpful.
ALKALI
Sources Amitraz is found in external lotions and dip used in
treatment of demodectic mange. Products known to contain amitraz include Mitaban
(Upjohn) and Preventic flea and tick collars. (Mitaban also contains
xylene [see Organic solvents and fuels). Dogs and cats have been poisoned by dermal
absorption after application of amitraz. Ingestion of the dip or accidental ingestion of a
portion of a collar are most commonly reported as the source of poisoning.
Mechanism of action Amitraz acts at alpha 2- adrenergic receptor
sites in the CNS and at both alphal and alpha 2-adrenergic receptor sites in the
periphery.
Clinical signs Vomiting, ataxia, staggering, and CNS depression or
sedation are noted. This may progress to coma. Central alpha 2- stimulation results in
bradycardia and hypotension. Peripheral vasoconstriction (and possibly hypotension)
contribute to pallor of the mucous membranes. Gastrointestinal hypornotility, hypothermia,
and hyperglycemia are often noted. Polyuria is noted within 2 to 3 hours of poisoning.
Seizures have been reported as a sign of amitraz intoxication. (It has been suggested that
sedation, ataxia, and even coma may additionally be signs of xylene toxicosis if
intoxication was caused by Mitaban [see Organic solvents and fuels]
Treatment Treatment of amitraz poisoning is best accomplished by decontamination of the
patient and administration of antidotes (yohimbine or atiparnizole).
Signs
Vomiting
Ataxia, incoordination, staggering
Sedation
Gastrointestinal hypornotility
Hyperglycemia
Pallor of mucous membranes
Hypotension
Bradycardia
Polyuria
Sedation or coma
Seizures(?)
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen
.
3. Secure venous access, Collect blood for laboratory
testing.
4. Administer fluids as needed to support blood pressure
and perfusion.
5. Control seizures if necessary.
Decontaminate
1. Induce emesis if safe to do so or perform gastric
lavage. In cases of Mitaban intoxication, induction of emesis is not
advisable because of the presence of xylene, an
organic solvent that is known to cause aspiration pneumonia.
2. Administer activated charcoal. Repeat dose every 3
to 4 hours.
3. Administer saline or osmotic cathartics.
DERMAL EXPOSURE
Wash thoroughly with warm, soapy water. Wear rubber gloves when bathing the patient; avoid
chilling the patient.
Administer antidotes or other indicated supportive care
1. Alpha-adrenergic receptor antagonists are antidotal.
Atiparnizole administered at 50 mcg/kg IM reverses signs within
10 minutes. Doses may be repeated every 3 to 4 hours if
necessary.
Yohimbine
Dogs 0.11 mg/kg IV slowly
Cats 0.5 mg/kg IV slowly
Or 50 mcg/kg atiparnezole given IM followed by 0. 1 mg/kg
yohimbine IM q6h.
2. Administer fluids to maintain hydration and urine
output.
Enhancement of elimination
Because of the effective nature of the antidotes, there is no reason to consider enhanced
elimination techniques.
Avoid
Avoid treating bradycardia with anticholinergic drugs such as atropine
References
Duncan KL: Treatment of amitraz toxicosis, J Am Vet Med Assoc 203(8):1115-1116, 1993.
Hugnet C, Buronfosse F, Pineau X, et al: Toxicity and kinetics of armtraz in dogs,
AmJVetRes 57(10):1506-1510, 1996.
Sources Diet pills, drugs used in the treatment of narcolepsy
and hyperactivity, illegal drugs ("uppers," "speed," and
"bennies"). Sustained-release preparations are available.
Mechanism of action Amphetamines are CNS stimulants with some
adrenergic properties. They are believed to stimulate the release of norepinephrine and
act directly on both alpha-1 and beta 1 -adrenergic receptor sites as well as inhibiting
monoamine oxidase. Amphetamines are rapidly absorbed from the GI tract; high
concentrations develop in the brain and CNS.
Clinical signs Signs in amphetamine poisoning include flushing or pallor
followed by restlessness, hyperactivity, tachypnea, tachycardia, tremors, hypertension or
hypotension, dysrhythmias, heart block, circulatory collapse, mydriasis, hyperthermia,
ptyalism, hypoglycemia, and lactic acidosis. Life -threatening toxicosis is rare because
of the large margin of safety between therapeutic and lethal doses (in people) though
deaths have been reported after ingestion of low dosages (1.3 mg/kg) of methamphetamine.
Treatment Sedatives are used, and external stimuli are minimized.
Fluids and perhaps steroids are used if shock develops. Urinary acidification with oral
ammonium chloride will enhance renal elimination (but use only if the pet is not
acidemic). Repeated doses of charcoal and cathartics are needed if sustainedrelease
products were ingested. Chlorpromazine or haloperidol are used to combat drug-induced
hyperthermia, convulsions, and hypertension. Diazepam is used for seizures; increased
intracranial pressure (ICP) should be treated with furosemide and mannitol or
corticosteroids (though no scientific data could be found to prove that corticosteroids
improve morbidity and mortality in treatment of increased ICP). The electrocardiogram
should be monitored for dysrhythmias.
Clinical findings
Flushing or pallor
Restlessness
Hyperactivity
Tachypnea
Tremors
Hypertension or hypotension
Dysrhythmias or heart block
Circulatory collapse
Mydriasis
Hyperthermia
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen .
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Control seizures.
5. Treat hyperthermia if present.
Decontaminate
I . Remove toxins by induction of emesis or gastric
lavage if ingestion was within the last 60 minutes.
2. Administer activated charcoal. Repeat dose every 3
to 4 hours.
3. Administer saline cathartics.
Administer antidotes or other indicated supportive care
I . Chlorpromazine at I to 2 mg/kg IV, IM q12h PRN or
haloperidol at I mg/kg IV. Chlorpromazine in higher doses
(10 to 18 mg/kg IV) have been reported to be
beneficial in dogs that have consumed large quantities of an amphetamine.
2. Furosemide, mannitol, and corticosteroids may be
indicated for treatment of increased intracranial pressure
3. Administer fluids to maintain hydration and urine
output.
Enhancement of elimination
Amphetamines are suitable for ion trapping by urinary acidification.
Ammonium chloride 100 to 200 mg/kg/day PO divided dose q8-12h (dog) or 20 mg/kg PO ql2h
(cat).
Contraindicated if rhabdomyolysis (myoglobinuria), renal failure, or acidemia is
present.
References
Kisseberth WC, Trammel HL: Illicit and abused drugs, Vet Clin North Am Small Anim Pract
20(2) : 405-418, 1990.
Sources Arsenic and arsenates are found in nature (pyrites and
sulfides) and are common ingredients in herbicides, defoliants, insecticides, ant baits,
and rodent baits. They may be found in insulation and some forms of vermiculite or may be
a by-product of metal ore refining. Several forms of arsenic are used as wood
preservatives. The ashes of treated wood may remain toxic.
Mechanism of action Soluble forms of arsenic are readily
absorbed through skin, mucous membranes, and the respiratory system and from the
gastrointestinal tract. Toxicity is influenced by the route of exposure, rate of
absorption, metabolic rate and excretion rate, and most important the type of arsenical
present. Arsenic maybe present as the trivalent form (arsenite) or the pentavalent form
(arsenate). Trivalent forms are 4 to 10 times more toxic than the pentavalent form. The
mechanism of action of the trivalent form is believed to be its ability to disrupt
cellular respiration by binding to sulfhydryl groups on several important enzymes.
Vasodilatation and loss of capillary integrity result in fluid losses and hypovolemia.
This occurs in all tissues rich in oxidative enzymes (such as lungs, kidney, liver) but is
most pronounced in the gastrointestinal tract. The mechanism of action of the pentavalent
forms has not been fully elucidated but may involve interference with vitamin B , and B 6
metabolism.
Clinical findings
ACUTE
Acute onset of gastroenteritis with severe abdominal pain
Staggering, weakness, and perhaps tremors
Salivation, vomiting
Odontoprisis
Diarrhea, perhaps bloody
Possible hematuria
Shock, thready pulses
Oliguria, dehydration
Death in hours to 2 or 3 days
SUBACUTE
Depression, anorexia Watery diarrhea, which may contain blood and shreds or pieces of
intestinal mucosa Polydipsia with polyuria initially followed by anuria Dehydration
Possible hematuria Rear limb weakness, paresis, paralysis Seizures may occur Death in 4 or
5 days
CHRONIC
Rarely diagnosed in veterinary medicine
Lackluster appearance with rough, dry hair coat
Skin may become paper thin and crack, secondary pyoderma
If respiratory system is affected, the animal may have tachypnea and
dyspnea, especially when excited.
Brick red oral mucous membranes may be seen.
Polydipsia
Laboratory findings
Results of biochemical profiles will reveal the systems involved, but results are
nonspecific.
Commonly see evidence of dehydration with hemoconcentration.
Specific tests would be indicated for the diagnosis of arsenic poisoning.
Liver, kidney, stomach, and intestinal contents may be analyzed for arsenic. Urine may
also be analyzed for presence of arsenicals.
EMERGENCY TREATMENT
Procedures
Stabilize the patient:
1. Secure the airway and ventilate if necessary.
2. Administer crystalloid fluids to treat hypovolemia and shock and to
maintain hydration.
3. Monitor and treat electrolyte imbalances caused by diarrhea.
4. Monitor blood gases (venous blood gas determination will be
appropriate if the patient has no respiratory signs) and treat
acidemia with sodium bicarbonate as needed.
Decontaminate
1. If ingested within the last I to 2 hours and no
other contraindications exist, induce vomiting.
2 If contraindication to emesis exists and the exposure has
been within the last 2 to 4 hours, gastric lavage is indicated. if
signs are pronounced, there is a relative contraindication
to performing a gastric lavage because of increased likelihood
of perforation.
3. Gastric lavage should be followed by administration
of activated charcoal. Cathartics are not indicated because diarrhea
usually results from poisoning.
4. Dermal exposure may require that the offending
substance be brushed or vacuumed off or removed by bathing. Care must
be taken to avoid contamination and exposure of the
caregivers to the offending substance. Masks, face shields, and other
precautions are advisable.
Administer antidotes or other indicated supportive care
I Administer dimercaprol (BAL) 3 to 4 mg/kg IM q8h
until recovery. in severe exposures, dose may be increased to 6 to 7
mg/kg IM q8h on the first day.
2 A new chelator that is more effective than
dimercaprol has recently been used in children. Succimer (meso-
dimercaptosuccinic acid, also listed as DMSA) is available
as Chemet (from McNeil Consumer Products, a division
of McNeil-PPC, Inc., Fort Washington, PA 19034). This
chelator has shown promise in the treatment of heavy
metal toxicosis in children and adults. It is known to have
greater specificity for arsenic and lead than calcium EDTA or
penicillarnme. Studies have shown succimer to be effective
in treating lead poisoning in dogs. The dose used in the study
was 10 mg/kg PO every 8 hours for 10 days. It has a wide
margin of safety.
3 Administer acetyleysteine. A study of the toxicity of
sodium arsenite in rats showed that administration of acetylcysteine
reduced the toxicity, It has the advantage that it can be
administered IV for acute arsenic poisoning.
DOSE:
Cat 140 to
240 mg/kg PO; then 70 mg/kg PO q6h for 3 days
Dog 280 mg/kg
PO loading dose; then 140 mg/kg PO q4h for 3 days
Acetylcysteine may be given intravenously if the
patient is vomitiing. It is recommended that the solution be
administered at the lower dose, diluted with D5W, and given
through a 0.2 mcm filter over 15 to 30 minutes.
4. Blood (whole blood, packed red blood cells, plasma) may
be necessary.
5. Dopamine may be required to support blood pressure
or urine production.
6. B vitamins in the fluids have been recommended.
References
Murphy MJ: Toxin exposures in dogs and cats: pesticides and biotoxins, J Am Vet Med
Assoc 205 (3):414-421, 1994.
Ramsey DT, Casteel SW, Fagella AM, et at: Use of orally administered succimer
(meso-2,3-dimercaptosuccinic acid) for treatment of lead poisoning in dogs, J Am Vet Med
Assoc 208 (3) :371-375, 1996.
ASPIRIN (ACETYLSALICYLIC ACID, SALICYLATE) Pepto-Bismol
Sources Many analgesic, antiinflammatory, antipyretic, and
anticliartheal (Pepto-Bismol) agents that contain salicylates are sold as OTC
preparations. Some keratolytic products contain salicylates.
Mechanism of action Acetylsalicylic acid inhibits cyclooxygenase, which
then inhibits production of certain prostaglandins, including protective prostaglandins of
the E series. High levels are known to directly stimulate the respiratory center (early)
to cause an initial respiratory alkalosis. High doses are also known to uncouple'
oxidative phosphorylation and may cause hyperglycemia and glycosuria.
Clinical signs The biologic half-life of aspirin is 7.5 to 8 hours in
dogs and 38 to 45 hours in cats at a dose of 25 mg/kg/day. The toxic dose in cats is
>25 mg/kg/day in cats and >50 mg/kg/day in dogs. Signs are noted within 4 to 6 hours
after ingestion of a toxic dose and include depression, vorniting, anorexia and lethargy,
tachypnea (caused by initial respiratory alkalosis), and hyperthermia. The vomitus may be
blood-tinged from GI ulceration. CNS depression leads to muscle weakness and ataxia; coma
and death can occur within I or more days. Gastrointestinal ulceration or perforation may
be seen after the administration of repeated doses over several days' duration. Anemia,
bone marrow depression, Heinz body formation (cats), and toxic hepatitis may occur.
Toxic signs may be seen at doses of Pepto-Bismol >7 mL/kg/day in dogs
and cats. Two tablespoons of PeptoBismol contain the salicylate equivalent of one 5-grain
aspirin tablet.
Treatment There is no specific antidote. The stomach should be emptied by
induction of emesis or lavage if within <2 hours of ingestion though there are
literature reports that gastric evacuation may be of value up to 12 hours after ingestion
of enteric-coated aspirin preparations. Multiple-dose activated charcoal is warranted.
Acid-base balance is corrected as needed; diuresis is instituted. Alkalinization of the
urine with sodium bicarbonate can be done to hasten urinary excretion, though this
requires intense monitoring and is difficult to achieve safely. Peritoneal dialysis allows
direct removal of salicylic acid from serum. Gastric ulceration or perforation is treated
as needed.
Clinical findings
Depression
Vomiting (possibly blood tinged)
Anorexia or lethargy
Tachypnea
Pulmonary edema (infrequent)
Hyperthermia or hypothermia (late)
Anemia
Bone marrow depression
Heinz body formation (cats)
Toxic hepatitis
Muscle weakness
Ataxia
Seizures
Cerebral edema
Coma
Death
Laboratory findings
Hyperglycemia or hypoglycemia are possible.
Respiratory alkalernia with metabolic acidosis early. Metabolic acidemia later.
Electrolyte abnormalities are common
Wide anion gap acidosis
Hypokalemia
Hypernatremia
Increased bleeding time
Anemia, possibly with Heinz body formation
Increased liver enzyme levels
Alkaline phosphatase (ALK-P)
AST
ALT
GGT
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen
.
3. Secure venous access. Collect blood for laboratory testing.
Administer fluids as needed to support blood pressure and
perfusion..
4. Control seizures.
5. Treat hyperthermia if present.
6. Treat pulmonary edema.
Decontaminate
1. Induce emesis or perform gastric lavage.
2. Administer activated charcoal. Repeat dose every 3 to 4 hours.
3. Administer saline or osmotic cathartics. Enemas may also be
indicated.
Administer antidotes or other indicated supportive care
1. There are no known antidotes.
2. Administer fluids carefully to initiate brisk diuresis.
Closely observe for onset of pulmonary edema.
a. Furosemide
b. Dopamine drip (I to 3 mcg/kg/min)
c. Mannitol is not usually recommended.
3. Treat increased intracranial pressure if suspected
4. Correct acid-base and electrolyte imbalances.
a. Sodium bicarbonate should be administered to
combat metabolic acidemia as well as induce renal elimination of
salicylates. Blood gases and
urine pH should be monitored carefully to guide dosage and avoid complications caused
by therapy. When blood gases
are not available, sodium bicarbonate may be administered at I to 2 mEq/kg IV very
slowly.
b.Hypokalemia must be corrected because potassium
depletion inhibits alkalinization of the urine.
5. Optional glucose
6. Protect the GI tract:
a. Administer sucralfate at 250 to 1000 mg for
dog q6-8h PO and 250 mg for cat q6-12h PO.
b. Administer misoprostol (Cytotec) at I to 5
mcg/kg q8-12h PO (dog only) for ulcer prophylaxis. Administer
omeprazole at 0.7 mg/kg
q24h PO for dog only. H 2-receptor antagonists have not been shown to be of benefit as a
prophylactic therapy
against NSAID-induced GI ulcers. Their use in aspirin intoxication is also questionable.
Enhancement of elimination
1 . Urinary alkalinization enhances urinary excretion
2. Hemodialysis is effective.
3. Hernoperfusion.
4. Peritoneal dialysis is effective.
References
Murphy NIJ: Toxin exposures in dogs and cats: drugs and household products, JAmVet Med
Assoc 205(4):557-560, 1994.
Oehme F: Aspirin and acetarninophen. In Kirk RW, editor: Current veterinary therapy, ed 9,
Philadelphia, 1986, Saunders.
B
Sources Sleeping pills, anticonvulsants, tissues of animals that
were euthanatized, and illicit drugs.
Mechanism of action Barbiturates are known to cause global depression of
neuronal activity in the brain. These effects are apparently mediated through enhancement
of gamma - aminobutyric acid (GABA)-mediated synaptic inhibition (by opening membrane
chloride channels). Barbiturates do not act directly on the chloride channel or GABA
receptors but affect an allosteric site that prolongs the increase in chloride -channel
conductance and facilitates GABA action. Different mechanisms of action may be seen in
different areas of the CNS by different doses of different barbiturates.
Clinical findings
SEVERE INTOXICATIONS
Coma, anesthesia
Hypothermia
Miosis or mydriasis
Respiratory depression, hypoxemia, hypercapnia, respiratory acidosis
Hypotension, reflex tachycardia
Depression of cardiac contractility
Splenornegaly
Death
MODERATE INTOXICATIONS
Hypothermia
Ataxia
Lethargy
Sleepiness
Nystagmus may be seen
Splenornegaly
Possible hypotension
Possible hypothermia
Laboratory findings
Barbiturates are easily detected with routine toxicologic screens.
EMERGENCY TREATMENT
Support the patient. Secure the airway and ventilate the patient if necessary. Treat coma,
hypotension, and hypothermia if they exist.
Decontamination
1. Induce emesis only if the ingestion was within the last 60
minutes and the patient shows no clinical signs.
2. Perform gastric lavage if the ingestion was within the last 2
to 4 hours.
3. Give repeated doses of activated charcoal.
4. Administer saline cathartic. Magnesium- containing solutions
should be avoided.
5. Consider whole bowel irrigation using CoLyte or GoLYTELY.
Enhanced elimination
Alkalinization of the urine has been shown to increase the elimination of phenobarbital
but none of the other barbiturates. Its value in acute overdose has not been proved, and
it may contribute to fluid overload and pulmonary edema.
Hemoperfusion is indicated for the severely overdosed patient.
Avoid
Lactate, glucose, and epinephrine if used improperly (at very
high doses) may cause prolonged effects of some of the
barbiturates. if these solutions are used properly, there
is no clinical significance.
Chloramphenicol will potentiate the effects of many of the
barbiturates and is contraindicated.
References
Dayrell-Hart B, Steinberg SA, VanWinkle TJ, Farnbach GC: Flepatotoxicity of phenobarbital
in dogs: 18 cases (1985-1989), J Am Vet Assoc 199(8):1060-1066, 1991.
Dumonceaux GA, Beasley VR: Emergency treatments for police dogs used for illicit drug
detection, JAm Vet Assoc 197(2):185-187, 1990.
Owens JG, Dorman DC: Drug poisoning in small animals, Vet Med 92(2):149-156, 1997.
SEE (Organic Solvents and Fuels)
SEE (Organic Solvents and Fuels)
Sources Household laundry
bleaches most commonly contain sodium hypochlorite at concentrations of 3% to 6%.
Industrial-strength bleaches and swimming pool supplies may contain 50% sodium
hypochlorite. other common ingredients in (nonchlorine or colorfast) bleaches include
trichloroisocyanuric acid and sodium perborate.
Mechanism of action Sodium hypochlorite is corrosive and usually
has local effects on the mucous membranes and esophageal tissues. Animals rarely ingest
enough bleach to cause systemic signs. Further, ingestion of a bleach solution usually re
sults in vomiting, limiting the quantity of toxic principal absorbed. The hypochlorite
bleaches are alkaline, and tissues exposed to it will suffer alkali burns.
Trichloroisocyanuric acid is corrosive but of low toxicity. Sodium perborate degrades to
hydrogen peroxide (which may cause gastritis and emesis) and borate (which may cause
systemic signs of boric acid poisoning,.
Clinical signs Most pets have a "bleach" odor and may show
bleaching of the hair. Ptyalism, emesis, and rebound tenderness of the cranial side of the
abdomen may occur. Hernaternesis and pharyngeal edema may be seen.
Treatment Although induction of
emesis within 3 hours of ingestion has been recommended by at least one reference, we ad
vise against this. Bleaches are alkalis, and the rules of alkali exposure should be
followed (pp. 70 to 72). Although most patients will vomit within minutes after ingestion
of common bleaches, vomiting should not be the goal of the veterinarian presented with a
case of bleach ingestion. Current advice for ingestion of bleaches includes administering
large volumes of water or milk.
Past recommendations included administering milk of magnesia, egg whites, or powdered milk
slurry. Baking soda (sodium bicarbonate) causes carbon dioxide formation
and gastric distension as well as formation of hypochlorous acid and should not be
given.
Signs
Bleach odor
Bleaching of hair
Salivation
Emesis, hematernesis
Rebound tenderness of cranial abdomen
Pharyngeal edema
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer large volumes of water or milk.
5. Administer analgesics.
6. Administer antidotes.
a. There are no known antidotes.
b. Milk of magnesia has been recommended at 2 to 3 mL/kg PO.
Decontaminate
GI EXPOSURE (INGESTION)
See step 4 above.
DERMAL EXPOSURE
Wash thoroughly with warm, soapy water. Wear rubber gloves when bathing the patient. Avoid
chilling the patient.
Enhancement of elimination
Administer fluids to maintain blood pressure or hydration and urine output.
Sources Borates and boric acid are contained
in many products including roach killers, flea products, fertilizers, herbicides,
antiseptics, disinfectants, and contact lens solutions. Sodium perborate is found in
mouthwashes and denture cleansers. Other boron-containing compounds include sodium borate,
sodium biborate, sodium pyroborate, sodium tetraborate, boric anhydride, boron oxide,
boron trioxide, boric oxide, boron sesquioxide, borax, sodium metaborate, and magnesium
perborate.
Mechanism of action The lethal oral dose for boric acid
for small mammals is 0.20 to 0.50 g/kg of body weight. Emesis usually occurs only after
substantial amounts of borate have been ingested. Borates are readily absorbed from the GI
tract. They are absorbed through abraded skin, but do not easily penetrate intact skin.
Borates are excreted in the urine, with 40% to 60% of the dose excreted within 12 to 24
hours. Blood concentrations of borate above 50 mcg/mL are diagnostic for borate poisoning.
The exact mechanism of action is not understood. Borates are generally cytotoxic to all
cells. Because borates are concentrated by the kidney and excreted in the urine, the
kidneys are often damaged more than other systems. The brain and liver are also known to
be damaged by borates.
Clinical signs Signs include ptyalism, diarrhea, abdominal
pain, rebound cranial abdominal tenderness, ataxia, hyperesthesia, tremors, muscle
weakness, metabolic acidosis, seizures, coma, and death. Mild hyperthermia, shock,
disseminated intravascular coagulation, and Cheyne-Stokes respiration occur.
Treatment Emesis or gastric lavage should be induced if
ingestion occurred within 2 hours. Although borates are poorly adsorbed by activated
charcoal, it is commonly recommended (in addition to adminstration of a cathartic). To be
effective in removing borates from a patient, activated charcoal would have to be
administered in dosages 5 to 10 times normal recommendations. This clinically impractical.
The use of activated charcoal in patients known to have ingested borates is therefore not
recommended. Persistent vomiting and seizures are controlled as needed. Hemodialysis is
known to be effective in humans and should be considered in pets.
Signs
Salivation
Diarrhea, possibly bloody
Abdominal pain
Rebound cranial abdominal tenderness
Ataxia
Hyperesthesia
Tremors
Muscle weakness
Seizures
Coma
Mild hyperthermia
Shock
Disseminated intravascular coagulation
Cheyne-Stokes respiration
Death
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Control seizures.
5. Treat hyperthermia if present.
6. Administer crystalloids fluids to maintain perfusion and blood pressure.
Decontaminate
GI EXPOSURE (INGESTION)
Induce emesis if recent ingestion and if signs are not present.
Gastric lavage if signs are present after ingestion (p. 52).
Administcr saline cathartic unless diarrhea already present.
DERMAL EXPOSURE
1. Wash thoroughly with warm, soapy water. Wear rubber gloves when bathing the
patient; avoid chilling the patient.
2. Administer antidotes and other supportive care
3. Induce a brisk diuresis Administer fluids at 2 or 3 times maintenance dose.
Monitor for signs of overhydration.
4. Administer furosemide if the patient has normal renal function and is adequately
hydrated.
Enhancement of elimination
Hemodialysis is effective. Peritoneal dialysis. Exchange transfusions.
Mechanism of action Bromethalin is a potent diphenylamine
neurotoxin that acts by uncoupling oxidative phosphorylation leading to decreased
Na+/K+-ATPase activity. Without normal Na+/K+-ATPase activity, the ability to maintain
normal cellular membrane potential and osmotic gradient is lost, Sodium flows into the
cell following its electrochemical gradient, and fluid follows resulting in swelling and
loss of function. Signs are related to CNS dysfunction. Death is usually caused by
respiratory paralysis.
Clinical signs Clinical signs are extremely variable depending on
amount of toxin ingested. High doses may result in onset of signs within hours, whereas
lower doses may not have noticeable effects for several days. High doses in dogs have
produced signs of hyperexcitability, tremors, hyperreflexia of the hindlimbs, running
fits, focal or generalized seizures, and death. Low doses produced depression, anorexia,
vomiting, tremors, paresis (of one or more limbs), paralysis, and death. Animals poisoned
with bromethalin have been noted to assume Schiff - Sherington posture or to have extensor
rigidity. Miosis and anisocoria have been noted. Cats have similar signs including
depression, ataxia, progressive motor dysfunction to paralysis, abdominal swelling,
convulsions, and death. Death is seen with low doses as well as with high doses.
Brornethalin poisoning should be suspected whenever acute signs of cerebral edema or
posterior paresis or paralysis are seen. Differential diagnosis includes alcohol
intoxication, ethylene glycol intoxication, salt poisoning, rabies, polyradiculoneuritis,
tick paralysis, and botulism.
Treatment Treatment mainly supportive because no antidote exists. Treatment
is aimed at decreasing absorption of the toxin and decreasing cerebral edema. Fluids
should be used carefully to prevent aggravation of the cerebral edema. Mannitol and
corticosteroids may be ineffective in treating bromethalin toxicity though they are
currently recommended in reducing cerebral edema from other causes. Activated charcoal
improves survivability when given early.
Signs
ACUTE EXPOSURE
Hyperexcitability
Severe muscle tremors
Running tits
Grand mal seizures
Hindlimb hyperreflexia
Depression
Death
CHRONIC EXPOSURE
Tremors
Depression
Ataxia
Vomiting
Lateral recumbency
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen .
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure
and perfusion.
5. Control seizures.
6. Treat hyperthermia if present.
Decontaminate
Induce emesis only if the ingestion was within the last 60 minutes and the patient shows
no clinical signs.
Perform gastric lavage if the ingestion was within the last 2 to 4 hours.
Give repeated doses of activated charcoal.
Administer saline cathartic. Magnesium-containing solutions should be avoided.
Consider whole bowel irrigation using CoLyte or GoLYTELY.
Administer antidotes or other indicated supportive care
There are no known antidotes.
Treat cerebral edema. (Treatment may not be effective in cases of edema known to be caused
by bromethalin.)
I . Furosemide
2. Mannitol administered at 0.1 to 0.5 g/kg IV slowly qI-6h PRN
3. Methylprednisolone sodium succinate at 25 to 30 mg/kg IV initially
followed by 12.5 to 15 mg/kg IV at 2 and 6 hours
later and then 2.5 mg/kg/hour IV continuous infusion
for 8 to 42 hours.
4. Dexamethasone sodium phosphate at 2 to 3 mg/kg IV followed by I mg/kg
SC q6-8h in doses tapering off.
Enhancement of elimination
There are no reported techniques (other than repeated doses of activated charcoal) that
are effective in enhancing the elimination of bromethalin from the body.
Avoid Drugs that might induce hypoventilation (such as high doses of narcotics or
tranquilizers).
References
Carson T: Bromethalin poisoning. In Kirk RW, Bonagura JD, editors: Current veterinary
therapy, ed 10, Philadelphia, 1989, Saunders.
Osweiler GD: Toxicology, Philadelphia, 1996, Williams & Wilkins, pp 286-288.
BUILDERS
See also Detergents, Soaps
Mechanism of action Builders, which bind elements in detergents and
are responsible for water hardness, act by inflicting caustic burns and inducing
hypocalcemia by binding calcium (oxalates). Common compounds in descending order of
toxicity include metasilicate, sodium carbonate or sesquicarbonate, polyphosphates,
silicates, and bicarbonates.
Clinical signs Similar to acids in causing highly corrosive
coagulation necrosis. Hypocalcemia may also be seen.
Treatment Treatment is aimed at flushing the mucous membranes
and other exposed areas with copious amounts of water. Calcium and diuresis with
intravenous fluids and furosemide may be needed in oxalate ingestions.
Signs
Highly corrosive coagulation necrosis
Hypocalcemia
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood for laboratory testing.
Administer fluids as needed to support blood pressure and
perfusion.
4. Treat hyperthermia if present.
Decontaminate
1. Induce emesis or perform gastric lavage if exposure was by ingestion.
2. Administer activated charcoal. Repeat close every 3 to 4 hours.
3. Administer saline or osmotic cathartics. Enemas may also be
indicated.
Administer antidotes or other indicated supportive care
1. Pulverized chalk, slurry of powdered milk (100 mL PO), lime water
(150 to 200 mL) may be given orally to precipitate
oxalates in the GI tract.
2. If signs of hypocalcemia are present, administer calcium gluconate
0.25 to 1.5 mL/kg IV slowly over 20 to 30 minutes
observing for bradycardia to effect if serum calcium
decreases.
3. Osmotic diuresis with mannitol 20% at 0. 1 to 0. 5 g/kg IV q1 -6h PRN
or furosemide at I to 5 mg/kg IV PRN qI-4h.
CAUTION: Furosemide may promote
calciuresis, thus enhancing hypocalcemia.
Enhancement of elimination
There are no known effective techniques.
C
CARBAMATES
see
ORGANOPHOSPHATES and CARBAMATES
Sources Combustion, fires, patients suffering
smoke inhalation, vehicles (automobiles, airplanes) with faulty exhaust systems,
improperly vented heaters.
Mechanism of action Carbon monoxide has an affinity for hemoglobin that
is 240 times greater than that of oxygen. When carbon monoxide is combined With
hemoglobin, it is known as carboxyhemoglobin. Carboxyhemoglobin causes a leftward shift of
the oxygen dissociation curve; that is, the oxygen is bound more tightly and is not
released to the tissues so readily.
Clinical findings The most characteristic finding in the patient
suffering carbon monoxide poisoning is cherry red blood (similar to cyanide) and red or
dark pink mucous membranes, skin, and other tissues. Blood gases may reveal hypoxemia or
acidosis; however they do not reveal the presence or absence of carbon monoxide. Blood gas
measurements are for the most part unaffected by the presence of carboxyhemoglobin. Oxygen
saturation levels are falsely normal when determined by pulse oximetry because
carboxyhemoglobin is "invisible" to this technologic method. Carboxyhemoglobin
may be detected using direct oximetry or co-oximetry, technologic methods not widely
available in veterinary medicine.
Signs
Signs noted depend on the level of carboxyhemoglogin. Carboxyhemoglobin levels of 10% or
higher will cause confusion and dyspnea. Additional signs include ataxia, lethargy,
deafness, seizures, psychornotor disturbances, and coma. Levels >60% (or sometimes
less) are fatal.
Tachypnea, dyspnea, hyperpnea
Signs of shock
Bright red mucous membranes
Collapse
Hypoxemia -induced mentation changes including confusion, dizziness (staggering),
seizures, and coma.
Agonal respirations followed by respiratory paralysis.
Cyanosis may be noticed soon after onset of hypoventilation. Classic finding is the cherry
red blood.
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen. Administer 80% to 100% oxygen for at
least 30 minutes. The half-life of
carboxyhemoglobin approaches 300 minutes in room air
but is decreased to about 30 minutes in 100 % oxygen.
3. Secure venous access. Collect blood for laboratory testing.
Administer fluids as needed to support blood pressure and
perfusion.
4. Control seizures.
Decontaminate
Remove the patient from the source of carbon monoxide.
Administer antidotes or other indicated supportive care
There are no known effective antidotes.
Enhancement of elimination
There are no known effective techniques other than administration of high levels of
oxygen.
CARBON TETRACHLORIDE
Taken internally, this chemical causes nausea and vomiting, diarrhea, collapse and death. Liver failure can also result from ingestion..
Treatment:External: Flush skin and remove any chemical as soon as possible, provide fresh air, remove cat from fumes, induce emesis or lavage followed by repeated doses of activated charcoal. Laxatives to clean out the GI tract. IV dextrose and calcium may also be given along with antidotes and medications to maintain kidney function. Immediate emergency treatment is necessary.
CHOCOLATE (THEOBROMINE) AND CAFFEINE POISONING
Sources Cooking, baking, candy, landscaping (with cacao shells),
white chocolate (negligible amounts of theobromine), sweetened milk chocolate (1/10 the
amount of theobromine as found in unsweetened chocolate, approximately 45 to 60 mg/oz),
semisweet or dark chocolate contains 130 to 185 mg/oz. Unsweetened (baking) chocolate (450
mg/oz), cocoa powder (150 to 600 mg/oz); coffee, tea, soft drinks.
Mechanism of action Theobromine inhibits phosphodiesterase, which
results in increased cAMP and release of catecholamines. Caffeine directly stimulates the
myocardium and central nervous system. It also causes a competitive antagonism of cellular
adenosine receptors. Increased muscle contractility is caused by increased entry of
calcium and inhibition of sequestration by the sarcoplasmic reticulum (mechanism unknown).
Benzodiazepine receptors in the brain are competitively antagonized.
Clinical signs
THEOBROMINE
A slight increase in blood pressure is seen. Bradycardia or more commonly tachycardia
occurs, and myocardial dysrhythmias, especially ventricular premature beats, are possible.
Central nervous system excitability, manifested as nervousness, excitement, tremors,
seizures, and ultimately coma, are seen. Panting and urinary incontinence are also
possible. Death occurs within 6 to 24 hours with acute exposure. With chronic ingestion
(over several days), death may result from cardiac failure.
CAFFEINE
Tachycardia, tachypnea, hyperexcitability, tremors, seizures, premature ventricular beats.
Dilatation of coronary, pulmonary, and systemic vessels may cause congestion or
hemorrhage. The lethal dose for caffeine is 150 mg/kg for dogs, cats, and people.
Treatment No antidote exists; treatment is supportive. Emesis
is used and may be effective even after several (4 to 6) hours have passed since
ingestion; gastric lavage is useful if emesis is only partially productive or
contraindicated. Activated charcoal is useful and can significantly decrease the half-life
of theobromine. Diazepam is used to control tremors, anxiety, or seizures. Bradycardia is
treated with atropine; tachycardias are treated with lidocaine, metoprolol, or
propranolol. The urinary bladder should be catheterized to prevent reabsorption of
theobromine through bladder mucosa. Fluids are given as part of supportive treatment.
Signs
THEOBROMINE
Mild hypertension
Bradycardia or tachycardia
Dysrhythmias (especially PVCs)
Nervousness
Excitement
Tremors
Seizures
Panting
Urinary incontinence
Coma
Death
CAFFEINE
Tachycardia Tachypnea Hyperexcitability Tremors Seizures Dysrhythmias (especially PVCs)
Generalized congestion or hemorrhage.
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Control seizures. Diazepam is indicated as first choice in
controlling seizures but is often ineffective because of the
antagonism of the benzodiazepine receptors. If
diazepam is ineffective, use phenobarbital followed by pentobarbital if
necessary.
5. Treat hyperthermia, if present.
6. Monitor ECG for cardiac dysrhythmias. Treat dysrhythmias when noticed
with generally accepted treatment options.
(See notes below.)
Decontamination
I . Although chocolate is not very effectively removed during vomiting
because of its "sticky" composition when melted, it is
still most commonly recommended to induce
emesis if ingestion was recent.
2. Gastric lavage with warm water will help to remove the melted
chocolate from the stomach. Cool or cold water may
actually worsen retrieval of chocolate.
3. Administer activated charcoal and a saline cathartic; repeat PRN
q4-6h
.
Administer antidotes or other supportive care
1. There are no effective antidotes.
2. Atropine (for bradycardia) at 0.02 mg/kg IV PRN.
3. Metoprolol. Dog: 0.5 to 1.0 mg/kg PO q8h; cat: 12.5 to 25 mg/cat PO
q8-12b (an IV dose has been published as 0.04
to 0.06 mglkg given slowly IV q8h; we have not used
this route of administration and would advise caution) or
propranolol (acute dysrhythmias: 0.02 to 0.06
mg/kg IV over several minutes; nonacute: dogs: 2.5 to 10 mg/dog PO
q8-12h; cats: 2.5 to 5.0 mg/cat PO q8-12h) for atrial
or ventricular tachycardias. NOTE: Metoprolol is the beta-blocker
of choice because propranolol is known to slow renal
excretion of xanthines (in humans).
4. Lidocaine (in place of metoprolol or propranolol for ventricular
tachycardias) at I to 2 mg/kg IV bolus followed by 25 to
75 mcg/kg/min IV infusion (dogs) or 0.25 to 1.0 mg/kg
IV bolus followed by 5 to 40 mcg/kg/min IV infusion (cats)
.
5. Administer fluids to support blood pressure and to maintain hydration
and urine output.
Enhancement of elimination
1. Fluid diuresis may enhance excretion.
2. Dialysis and ion trapping are not effective.
Avoid
1. Erythromycin and corticosteroids are known to interfere with
excretion of methylxanthines.
2. Hypoventilation
References
Hooser S, Beasley V: Methylxanthine poisoning (chocolate and caffeine toxicosis), in Kirk
RW, editor: Current veterinary therapy, ed 9, Philadelphia, 1986, Saunders.
Murphy MJ: Toxin exposures in dogs and cats: drugs and household products, J Am Vet Med
Assoc205(4):557-560, 1994.
Owens JG, Dorman DC: Drug poisoning in small animals, Vet Med 92(2):149-156, 1997.
CHLOROPHENOXY DERIVATIVES
Clinical signs:
Ingestion of these chemicals cause stiffness, weakness, staggering, paralysis, coma and death.
Treatment:Flush and wash skin and mouth. Pump and flush the stomach. IV fluids to flush the kidneys and good general supportive care are important.
CHOLECALCIFEROL (Quintox, True Grit Rampage, Ortho Rat B-Gone)
Clinical signs:
Clinical signs of poisoning in cats will not often show for 2-4 days after ingestion. Vomiting, depression, anorexia, diarrhea, Polydipsia (greater than normal water consumption) and Polyuria (greater than normal urine production) and frequent urination, and increased body temperature have all been reported. Death usually occurs 4-7 days after exposure.
Treatment:Induce emisis if early (within 3 hours). Administer activated charcoal. IV fluids including calcium, cortisone, diuretics, and calcitonin can all be used. Most cats survive with proper care. Feeding milk may also be helpful.
CITRUS OILS
Clinical signs:
Extremely toxic. See: (+)-LIMONENE,
LINALOOL, CRUDE CITRUS OIL EXTRACTS
COCAINE
Sources Commercial preparations include topical and local anesthetics.
Free-based cocaine is called "crack," "rock," or "flake."
illicit cocaine may contain impurities including other ,came" anesthetics, caffeine,
amphetamine, or quinine.
Mechanism of action Cocaine is rapidly absorbed from mucous membranes,
whereas there is a slight delay of absorption from the GI tract. Cocaine causes an initial
sympathetic discharge by interfering with reuptake of endogenous catecholamines. It also
is known to interfere with reuptake of doparnine resulting in an increase in dopaminergic
neurotransmission. Direct cardiotoxicity is seen with large doses.
Clinical signs Cocaine causes CNS excitement, peripheral
vasoconstriction, increased muscle activity, and secondary hyperthermia. Depression may
follow stimulation. Death is caused by the effects of hyperthermia, respiratory arrest, or
cardiac arrest.
Treatment Emesis followed by charcoal and a cathartic. Because cocaine is
rapidly absorbed from the GI tract (which may make emesis ineffective), gastric lavage
maybe preferable. Surgery is needed if bags of cocaine are ingested. if surgery is not an
option, consider whole bowel irrigation using polyethylene glycol solutions such as CoLyte
or GoLYTELY. Chlorpromazine may antagonize many of cocaine's effects and may control
hyperthermia, though it should not be used if seizures are present because phenothiazines
are known to aggravate seizures. Seizures are controlled with diazepam or barbiturates;
hyperthermia is treated as needed (see Hyperthermia, p. 30). Respiratory support should be
assisted as needed.
CYANIDE ***WARNING*** EXTREMELY TOXIC***
Sources Fires, cyanogenic plants (apricot pits, Prunus spp., Sambucus spp., cassava, etc.), photographic chemicals, plastic manufacture, laboratories, drugs (nitroprusside). it has been used as a rodent fumigant and in baits to kill wild animal pests such as the coyote. Hydrogen cyanide gas is a by-product of combustion of many substances found in homes; thus cyanide toxicity is common in animals trapped in burning buildings.Mechanism of action Cyanide irreversibly combines with the ferric ion of cytochrome oxidase to form a stable complex. The blood can become oxygenated, but the cells are blocked from utilizing it. Increased respiratory rate and effort "superoxygenate" the blood giving it a cherry red color.
Clinical findings Depends on the source and amount. Inhalation of large quantities of cyanide are rapidly fatal (minutes).
Tachypnea, dyspnea, hyperpnea
Signs of shock
Bright red mucous membranes
Shock and collapse
Hypoxemia -induced mentation changes including confusion, dizziness (staggering), seizures, and coma.
* Agonal respirations followed by respiratory paralysis.
Cyanosis may be noticed soon after onset of hypoventilation.
Classic finding is the cherry red blood.
Stomach contents may have a bitter almond smell.
EMERGENCY TREATMENT
Procedures
1. Remove the patient from the source of cyanide if possible. Rescuers should wear self-contained breathing apparatus.
2. Secure the airway and ventilate as necessary .
3. Administer supplemental oxygen .
4. Secure venous access. Collect blood and urine for laboratory testing.
5. Administer isotonic crystalloids as needed to support blood pressure and perfusion.
6. Control seizures .
Decontaminate
I If inhaled, remove the patient from the source. Rescuers should wear self-contained breathing apparatus.
2 If a known cyanide -containing substance was ingested
within the last 15 minutes and no signs are present, induce
vomiting.
3. If a known cyanide -containing substance was ingested within
the last 15 to 60 minutes and no signs are present, perform
gastric lavage.
4. Although cyanide is generally not adsorbed by activated charcoal,
administration of activated charcoal may be of value if
the toxin was ingested.
5. If there is dermal exposure (such as that from a fire or exposure
to a chemical form of cyanide), bathe the animal
thoroughly with soap and water. Avoid induction of
hypothermia.
6. Administer antidotes or other indicated supportive care
I . 1.65 mL/kg 25% sodium thiosulfate IV.
2. Only if the diagnosis of cyanide is certain should sodium nitrite
be administered (16 mg/kg IV). This drug may cause
nitrite-induced methemoglobinemia, which could
be fatal if cyanide poisoning is not present.
3. Hydroxocobalamin is an investigational drug that shows much
promise in the treatment of cyanide toxicosis. It is currently
not available in the United States.
4. Dicoball edetate is used in -the United Kingdom but is not
available in the United States. Dicobalt edetate forms a
nontoxic stable ion complex with cyanide.
5. Amyl nitrate is used as an antidote in humans, but literature regarding its use in dogs and cats was not found.
Enhancement of elimination
Hemodialysis may be of value in patients who have developed high thiocyanate (a less toxic compound from cyanide metabolism) levels.
DECONGESTANTSSources Many over-the-counter cold and allergy preparations contain decongestants. The common decongestants include ephedrine, oxymetazoline, phenylephrine, pseudoephedrine, and phenylpropanolamine.
Mechanism of action Most decongestants are sympathornimetic amines. The action produced by each compound depends on the adrenergic receptor or receptors that are activated. Phenylpropanolamine and phenylephrine are primarily alpha -adrenergic agonists though phenylpropanolamine also produces mild beta, -adrenergic receptor stimulation and acts indirectly by enhancing norepinephrine release. Ephedrine and pseudoephedrine stimulate both alpha- and beta-receptors. The clinical signs are more closely related to beta -stimulation than alpha -stimulation with these two drugs.
Signs Dogs are more frequently intoxicated than cats. Signs include restlesness, hyperactivity, pacing, and apparent hallucinations (flybiting, wincing, dodging invisible menaces). Most dramatic is the intensity with which these patients seem to ,need" to keep in motion. Tachycardia is often noted but cannot be assumed because bradycardia may manifest as a response to hypertension. If blood pressure measurement is possible, moderate to severe hypertension will most likely be noted. Hyperactivity may progress to seizures. Mydriasis is common. Tachypnea with hyperventilation and hyperthermia are noted.
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary .
2. Administer supplemental oxygen .
3. Secure venous access if possible (see note below). Collect blood for laboratory testing.
4. Control seizures .
5. Treat hypertension .
6. Treat hyperthermia if present
.
Decontaminate
1. Do not induce emesis unless the patient ingested the medication within the last 5
minutes. Perform gastric lavage if
exposure was within the last 60 minutes.
Sustained -release types of these compounds are common; thus gastric lavage
may be beneficial past the recommended 60
minutes.
2. Administer activated charcoal. Repeat dose every 3 to 4 hours.
3. Administer saline or osmotic cathartics . Enemas (DO NOT USE FLEET ENEMA-TOXIC) may also be indicated.
Administer antidotes or other indicated supportive care
1. There are no known effective antidotes.
2. Administer fluids to maintain hydration and urine output.
3. Monitor electrocardiogram for cardiac dysrhythmias and treat as indicated.
4. Treat increased intracranial pressure if suspected by neurologic examination.
Enhancement of elimination
Urinary acidification may enhance elimination but may worsen renal damage if rhabdomyolysis accompanies intoxication.
Avoid1. Avoid using propranolol for dysrhythmias or hypertension without first administering
a vasodilator; paradoxic worsening
of hypertension may result.
2. Do not use atropine to treat bradycardia or AV block associated with hypertension.
The bradycardia is a protective
reflex and, if removed, may worsen the
hypertension.
DEET (N,N-diethyl-m-toluamide)
Sources Insect repellants such as Off, Deep Woods Off, and
Cutters are examples of pure DEET (or deet) products. Hartz
Blockade is a repellent and insecticide product containing DEET and fenvalerate
(a pyrethroid).
Mechanism of action Has not been fully elucidated.
Clinical signs Vomiting, tremors, excitation, ataxia and seizures have
been reported in dogs and cats where deet was suspected as the toxic product. Irritation
of the skin is also a possibility.
-
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen .
3. Secure vt!nous access. Collect blood and urine for laboratory
testing.
4. Administer isotonic crystalloids as needed to support blood pressm~
and perfusion.
5. Control seizures.
6. Treat hyperthermia if present
.
Decontaminate
induction of emesis is relatively contraindicated.
Perform gastric lavage if the ingestion was within the last 2
hours.
Give repeated doses of activated charcoal.
Administer saline cathartic. Cathartics containing magnesium
should be avoided.
Consider whole bowel irrigation using CoLyte or GoLYTELY.
Bathe the patient in liquid dishwashing detergent or mild
shampoo. Continue for at least 15 minutes or until the odor is
gone.
Administer antidotes or other indicated supportive care
There are no known antidotes.
Enhancement of elimination
There are no reported techniques that have been effective.
Reference:
Dorman DC: Diethyltoluamide (DEET) insect repellent toxicosis, Vet Clin North Am Small
Anim Pract 20 (2):387- 391, 1990.
DIGITALIS
Clinical signs:
Often found dead. Occasionally terminal seizures are observed. Vary from mild gastrointestinal upset (anorexia, vomiting, diarrhea) to terminal arrythmias. Slowed atrioventricular conduction will progress to AV block followed by ventricular rhythms.
Treatment:Note: Treatment is rarely possible.
The gastrointestinal tract should be decontaminated. induction of emesis or gastric ravage should be performed as needed, followed by administration of activated charcoal. Cathartics should also be used if necessary. Treat as for digitalis overdose.
Source Herbicide
Mechanism of action Dinoseb (2-sec-butyl-4,6-dinitrophenol) prevents the electron transport-coupled oxidative phosphorylation of ADP to ATP (it uncouples oxidative phosphorylation).
Clinical signs Signs of intoxication include tachypnea, weakness, disorientation, ataxia, and difficulty walking. Differential diagnosis includes organophosphate and organocarbarnate toxicoses.
Treatment Atropine or any agent that may contribute to hyperthermia is contraindicated. Treatment includes bathing to remove the toxicant; emesis, lavage, and catharsis; treatment of hyperthermia; avoidance of stress, which might increase body temperature; administration of fluids to prevent or treat shock, correct dehydration, and prevent electrolyte imbalances; administration of agents (such as dextrose or oral alimentation) to maintain a positive nitrogen balance; and administration of oxygen as needed.
EMERGENCY TREATMENT
ProceduresI . Secure the airway and ventilate as necessary
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Control seizures.
5. Treat hyperthermia if present. Atropine is contraindicated.
6. Support hydration to maintain blood pressure or hydration and urine output with
fluid therapy.
Decontaminate
GI EXPOSURE (INGESTION)
Induce emesis if recent ingestion if signs are not present
Gastric lavage if signs are present after ingestion.
Administer activated charcoal and a saline cathartic; repeat PRN q4-6h.
DERMAL EXPOSUREWash thoroughly with warm, soapy water. Wear rubber gloves when bathing the patient; avoid inducing hypothermia.
Administer antidotes or other supportive care
There are no known antidotes.
Reference
Murphy M: Toxin exposures in dogs and cats: pesticides and biotoxins,
Source Diquat dibromide is an active ingredient in herbicides.
Mechanism of action Diquat metabolism releases free radicals, which cause cellular membrane damage and cell death.
Clinical findings Animals poisoned with diquat have GI signs such as anorexia, vomiting, and diarrhea. Massive loss of body fluids occurs as they are "third spaced" in the gastrointestinal tract. Signs of acute renal failure including anuria, oliguria, or polyuria, isosthenuria, and renal tubular casts are noted with some frequency. CNS excitement occurs in severely poisoned animals.
EMERGENCY TREATMENT
Procedures
Treatment for diquat ingestion is much the same as for paraquat.Decontaminate
1. Induce emesis if ingestion was within the last 30 to 60 minutes.
2. Perform gastric lavage if indicated .
3. Administer adsorbent. Kaolin, clay, or bentonite is preferred over activated
charcoal. Pulverizedclay kitty litter is an
appropriate adsorbent. if none of these
products is immediately available, activated charcoal is preferable to waiting for
acquisition of a clay.
4. Administer a saline or osmotic cathartic if ingestion was within the previous 12 hours.
Administer antidotes or other indicated supportive care
There are no known antidotes. Administer crystalloid fluids to maintain hydration and urine output. In diquat poisoning, the main problems are not associated with lung injury but
with brain and kidney damage. Because
acute renal failure is a common sequela,
diuresis with mannitol, furosemide, and crystalloid fluids may be helpful. Monitor
urine output.
Other agents that have been used experimentally in diquat toxicosis include:
Niacin
Riboflavin
Ascorbic acid
Superoxide dismutase
N-Acetylcysteine
Enhancement of elimination
Diuresis may be helpful, but care must be taken to avoid adding to potential of development of pulmonary edema.
Dialysis may be useful but may contribute to pulmonary edema.
Hemoperfusion is effective in removing the toxin if begun early after exposure.
Avoid
Oxygen is contraindicated early in diquat poisoning. Oxygen administration may cause
increased formation of oxyradicals.
DNP
Clinical signs:
Mild fever, rapid breathing,, restlessness, seizures and death from respiratory failure.
Treatment:Reducing body temperature, administration of IV dextrose, oxygen and pumping the stomach.
ETHYLENE GLYCOL (ANTIFREEZE)
Sources Antifreeze, color film processing solution
Mechanism of action Ethylene glycol is metabolized by the liver using alcohol dehydrogenase in the first step of the pathway. Metabolites that are produced include glycoaldehyde (which causes CNS depression, including respiratory depression), glycolate (which causes metabolic acidosis), and oxalate (which combines with calcium to form calcium oxalate crystals, which precipitate in the renal tubules causing renal damage; oxalate also contributes to metabolic acidosis).
Many brands of antifreeze' contain phosphorus rust inhibitors; monitor phosphorus and treat hype rphosphaternia if needed.
Clinical signs The minimum lethal dose of undiluted ethylene glycol is 4.2 to 6.6 mL/kg for dogs (4.5 oz for a 20 lb dog) and 1.5 mL/kg for cats (I tablespoon of ethylene glycol diluted 50:50 with water in radiator fluid in the average-sized cat). There are three stages of poisoning, the first two are often not noticed by owners (and may not be present if the animal is brought for treatment immediately after it has consumed the product).
Stage I occurs 30 minutes to 12 hours after ingestion and includes nausea, vomiting, depression, ataxia, seizures, and rarely coma and death. These signs are similar to acute alcohol intoxication and resemble drunkenness. Polyuria and polydipsia often occur within I hour after ingestion.
Stage 2 occurs 12 to 24 hours after ingestion and includes tachycardia and tachypnea.
Stage 3 occurs 24 to 72 hours after ingestion in dogs and 12 to 24 hours after ingestion in cats. This stage is characterized by oliguric renal failure; signs include severe depression, vomiting, diarrhea, azotemia, and oliguria.
Increased osmolality, increased osmol gap, and high anion gap metabolic acidosis (which
is seen within 3 hours after ingestion) occur. Low urine specific gravity (<1.020) is
also seen within 3 hours after ingestion. Calcium oxalate or hippuric acid crystals, or
both, are occasionally but not always seen in the urine. The oxalate crystals can be the
more common monohydrate form or the dihydrate form. Calcium oxalate crystals are
occasionally seen in normal pets.
There is a test for ethylene glycol intoxication (PRN, Pharmacol Inc., Pensacola, Fla.) that can be used to support a diagnosis. This test will detect only ethylene glycol but not the toxic metabolites. Therefore the test must be run soon after ingestion to detect the ethylene glycol before metabolism. The test is not sensitive enough for cats. A positive test on cat blood means the cat has ingested a lethal dose and must be treated aggressively. A negative test on a cat is meaningless; cats are so sensitive to ethylene glycol that the color control used in the test has more than a feline lethal dose in it. A negative test on a dog indicates that the dog does not have lethal amounts of ethylene glycol in the circulation at the time of testing. it does not mean that the patient did not ingest antifreeze; it is possible that metabolism has reduced ethylene glycol levels lower than detectable by the test. The test cross-reacts with propylene glycol and other chemicals, and so it must be run on blood drawn before any medications are given (including activated charcoal). Antifreezes containing propylene glycol (Sierra, ARCO) are "safe" and are unpleasantly flavored to prevent ingestion. These "safer" compounds will not be metabolized to oxalate but could possibly cause problems related to the propylene glycol (Heinz body anemia).
Treatment The toxin is removed from the GI tract if recently ingested. Intravenous fluids are used to correct dehydration and metabolic acidosis. Ethanol, which is preferentially metabolized by alcohol dehydrogenase, is the mainstay of treatment. 4-Methylpyrazole is antidotal in dogs. Sodium bicarbonate is used to correct metabolic acidosis.
Signs
STAGE 1
Polyuria, polyclipsia Nausea Vomiting Depression Ataxia Seizures increased osmolality, increased osmol gap, and high aniongap metabolic acidosis Hyperglycemia Low urine specific gravity (<1.20) Calcium oxalate crystals (occasionally) Coma or death (rare in stage 1).
STAGE 2
Tachycardia, tachypnea
STAGE 3
Oliguric renal failure (azotemia, oliguria)
Severe depression
Vomiting
Diarrhea
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure and perfusion.
Monitor urine output, being especially
vigilant for oliguria or anuria.
5. Control seizures.
6. Treat hyperthermia if present.
Decontaminate
Induce emesis only if the ingestion was within the last 60 minutes and the patient shows no clinical signs. Perform gastric lavage if the ingestion was within the last 2 to 4 hours. Give repeated doses of activated charcoal. Consider appropriate use of saline cathartic.
Administer antidotes or other indicated supportive care.
4-METHYLPYRAZOLE
Fornepizole (4-methylpyrazole) has recently been approved for use in dogs (Antizol-Vet, Orphan Medical, Minnetonka, MN 55305). This synthetic alcohol dehydrogenase inhibitor is considered to be as effective as ethanol (possibly more effective) but has fewer side effects; thus it is the recommended antidote for ethylene glycol ingestion in dogs. The 1. 5 mL vial of fomepizole is diluted with 30 ml, of 0.9% sodium chloride to be used as an injection (provided with the kit). A loading dose of 20 mg/kg is administered IV. At 12, 24, and 36 hours after the initial loading dose of Antizol-Vet, doses of 15, 15, and 5 mg/kg should be administered respectively. If ethylene glycol is still detected in the bloodstream of the dog after this, the clinician should continue to dose the dog with 5 mg/kg IV every 12 hours until ethylene glycol does not remain in the bloodstream or the animal has visibly recovered. 4-MP should not be used in cats.
IV ETHANOL (ETHYL ALCOHOL)
The preferred method of administration of ethanol is by constant IV infusion. For continuous IV infusion:
Administer a loading dose of 600 mg/kg, followed by a continuous maintenance infusion of 100 mg/kg/hour. Administer this in fluids such as lactated Ringer's solution or half-strength saline at a rate suitable to provide one and one half times the maintenance needs.
Pure ethanol contains 754 mg/mL, and so 190 proof contains approximately 715 mg/mL.
Using a 20% solution is recommended in some texts. It is given at 5.5 mL/kg IV q4h for 5 treatments and then q6h (dogs) for 4 treatments. Cats are treated with 5 mL/kg q6h for 5 treatments and then q8h for 4 treatments. IV ethanol is usually 100% effective if started within I hour after ingestion. By 4 hours after ingestion, therapy is less effective because of the rapid metabolism of ethylene glycol.
SODIUM BICARBONATE
Sodium bicarbonate is used to correct metabolic acidosis. The amount to give is based on the bicarbonate deficit.
Bicarbonate deficit = 0.3 X Body weight (kg) X Base
deficit
Replace '/4 to '/2 of the calculated bicarbonate deficit slowly IV (over I hour); monitor the bicarbonate q4-6h and administer more as needed. If bicarbonate monitoring is not available, an alternative schedule of sodium bicarbonate administration has been recommended:
Dogs Sodium bicarbonate (5%) IP at 8 mL/kg q4h X 5 and then q6h for 4 additional treatments.
Cats Sodium bicarbonate (5%) IP at 6 mL/kg q6h X 5 and then q8h for 4 additional treatments.
Enhancement of elimination
Peritoneal dialysis is known to be highly effective in removing ethylene glycol if used early. The dose of IV alcohol should be doubled during peritoneal dialysis.
Clinical signs:
The effect of the fertilizer depends on the type of constituents found in the product. Increased salivation, ulcers in the mouth, vomiting, abdominal pain, fever, rapid heart rate, tremors, weakness and seizures are all possible from the ingestion of fertilizers.
Treatment:Flush and pump the stomach as early as possible and give activated charcoal. Giving milk THEN inducing vomiting is another option. IV fluids and electrolytes are also important.
FLUOROACETATES (COMPOUND 1080 and COMPOUND 1081)
Cats are extremely susceptible to this poison. Cats will vomit, defecate and urinate, frequently straining, trouble breathing, followed by bursts of wild activity mostly characterized as running fits, which are characteristic for poisoning by Compound 1080 and Compound 1081. Other symptoms of poisoning by these compounds are howling and/or crying, tremors, seizures and death unless treated immediately. Compound 1080 is the sodium salt, and compound 1081 is fluoroacetamide..
Treatment:Induce emesis. Gastric lavage if within 2 hours of ingestion. IV fluids, dextrose, calcium, and anesthesia are all used but the prognosis is very poor if moderate or large amounts of poison have been ingested. Antidotal medication is available. Early treatment will be needed to save the life of the cat.
Clinical signs:
When eaten, fluoride will cause salivation, vomiting blood, abdominal pain, decreased heart rate with weak respiration, convulsions and blood in the urine.
Treatment:The stomach should be flushed with certain calcium containing medications, IV fluids
and calcium, and generalized cardiac and respiratory support is all needed.
G
GARBAGE AND FOOD INTOXICATIONS
Sources Food-related poisonings are more prevalent in the warmer months
and during the holidays than at other times. Poisoning occurs as a result of ingestion of
food contaminated by microorganisms or their toxins. Common organisms and toxins
implicated in food poisoning include Escherichia coli, Staphylococcus, Streptococcus, and
Salmonella spp.; Clostridium perfringensand Clostridium botulinum (see Botulism);
and Bacillus spp.
Mechanism of action Enterotoxemia causes altered gastrointestinal
biochemical pathways and activation of autocoids (prostaglandins, kinins, etc.) that leads
to altered motility, permeability, and CNS interactions.
Endotoxemia, which results from absorption of endotoxin released in the GI tract, may be
seen as life - threatening endotoxic shock. Endotoxin is a lipopolysaccharide released
from the cell wall of dead bacteria (mostly gram negative). Upon absorption from the
gastrointestinal tract, the endotoxin acts through numerous mechanisms to initiate
cascades or events that cause deleterious effects throughout the body. There are many
texts that cover the syndrome quite well; the full syndrome is not covered in this text.
Suffice to say that, untreated, endoloxemia is a severe, life-threatening disease that
leads to shock, disseminated intravascular coagulopathy, pulmonary thromboembolism, acute
respiratory distress syndrome, systemic inflammatory response syndrome (SIRS), multiple
organ dysfunction syndrome (MODS), and death.
Clinical signs Pets suffering enterotoxemia often vomit, usually within 3
hours after eating the contaminated or spoiled substance. Vomiting may remove the
offending substance or substances, effecting a cure. Diarrhea, often bloody, may be seen
if signs progress, and it develops 2 to 48 hours after food ingestion. Recovery normally
occurs within 48 hours.
Protracted vomiting and diarrhea, along with permeability changes in the gastrointestinal
tract caused by the toxin, may result in significant fluid losses and electrolyte
imbalances. Early in the course of enterotoxicosis, hypermotility of the gastrointestinal
tract may be noted. This may be followed in 12 to 72 hours by ileus and gas accumulation
in the gut lumen. Gut stasis favors the growth of gram-negative bacteria, which may lead
to enclotoxemia.
Signs of endotoxemia are seen 5 to 48 hours after ingestion and include fever, vomiting,
and possibly diarrhea. in severe intoxications, signs of endotoxic shock including
depression, collapse, rapid-to-slow capillary refill time, hypotension, hypothermia or
hyperthermia, early leukopenia and neutropenia followed by leukocytosis and neutrophilia
with toxic neutrophils, hyperglycemia (early), or hypoglycemia (late), and oliguria may be
seen.
Treatment Food intoxications can mimic serious problems such as gastric
or intestinal torsions and foreign bodies. A thorough work-up including radiographs is
warranted to ensure proper diagnosis and treatment!
In cases where vomiting has occurred, the patient may have purged himself, thus requiring
only supportive care (fluids, activated charcoal with a cathartic). If vomiting has failed
to purge the stomach, treatment is by gastric lavage, repeated doses of activated
charcoal, and perhaps use of a cathartic. Antiernetics may be necessary if vomiting
continues after decontamination of the GI tract. Kaopectate can be used as an adsorbent or
gastrointestinal protectant. Fluids are given as needed to treat hypovolemia, shock, or
dehydration. Broad-spectrum antibiotics are given at the doctor's discretion.
Enterotoxemia cases may appear to go well only to relapse. If relapse occurs, it usually
does so within 48 hours. This may be related to onset of gut stasis and endotoxemia.
GASOLINE
Clinical signs:
External contact can cause skin irritation and vapors can be inhaled or fluid ingested by licking.
Inhalation can cause mild to moderate respiratory irritation, muscular twitching, dilated pupils and convulsions leading to death.
Ingestion leads to salivation, vomiting, diarrhea, muscle twitching and seizures.
Treatment:Fresh air should be provided to decrease the inhalation of more fumes. Skin should be
flushed well with water, and washed with soap and water. Oxygen therapy, IV fluids,
pumping the stomach followed by giving olive oil to coat the stomach are useful. With good
care most cats do quite well.
GINSENG
Sources Dried roots of plants of the genus Panax are
touted as a tonic for increasing strength and alleviating fatigue.
Mechanism of action Saponins called ginsengosides are believed to
be the active ingredients. The saponins decrease blood glucose and liver cholesterol,
increase erythropoiesis, hemoglobin production, and iron absorption from the G1 tract,
stimulate the CNS, and increase blood pressure, heart rate, and GI motility. Toxicity is
unlikely and has occurred only at extremely high levels. Supportive treatment (fluid
therapy, seizure control) may be needed but is unlikely.
-
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Control seizures. Check for hypoglycemia and treat if necessary.
5. Treat hypertension if necessary.
GLUE
Clinical signs:
Most glues cause local dermatitis and occasionally will ulcerate lips or gums if eaten. Vomiting can occur if swallowed.
Treatment:Remove any material using water and gentle pressure. Avoid solvents as these too may be toxic. Supportive care is important if vomiting occurs. Most cats recover well.
HERBICIDES
See also Dinoseb, Diquat and Poraquat
Sources Preernergent and postemergent products for weed control including
Betasan (bensulide), Round-up (glyphosate), Aatrex (atrazine), Banvel (dicamba),
OrthoParaquat/Gramoxone/Surefire/Cyclone/Prelude (paraqUat). Herbicides are rarely
responsible for severe toxicosis in pets, although G1 signs may be seen. Most pets could
not consume enough toxin from eating treated lawns. Rather, toxicity is more likely caused
by ingestion of the product directly. The risk of canine lymphoma was reportedly increased
(doubled) when owners applied 2,4-D ([2,4-dichlorophenoxy I acetic acid) several times per
year, though the Conclusions reached in this epiderniologic survey have been questioned.
oral and dermal exposure to lawn where diluted liquids or granules are properly applied
are generally of neglible risk.
Mechanism Of action 2,4-D causes anorexia, lethargy,
myotonia, and metabolic acidosis when an acute lethal dose is ingested Concentrated
formulations are irritating and may produce gastroenteritis. The LD,() (mediurn lethal
dose) for dogs is approximately 100 mg/kg; a 20 kg dog could consume this dose by
ingesting only 10 mL of a liquid formulation containing 23% of the acid equivalent of
2,4-D; however, it is unlikely that an animal Could consume a lethal dose after
application of a properly diluted formulation. Mecoprop (MMCP) is toxicologically similar
to 2,4-D. Atrazine and dicamba are not likely to be toxic unless chronic exposure occurs.
Monosodium methane arsenals (MSMA), disodiurn methane arsenate (DSMA), and octyldodecyl
ammonium salts of methyl arsenic acid are used as postemergents and do not have a high
acute toxicity. Signs and treatment of acute arsenic poisoning are discussed elsewhere .
Paraquat intoxication (1). 208) causes seizures, hyperexcitability, and
incoordination. Surviving pets may die 3 to 5 days later from severe pulmonary congestion
(pulmonary edema may develop within I to 3 days) or may develop pulmonary fibrosis in 7 to
10 days. Concentrated solutions are corrosive to the eyes and skin. Oxygen increases the
toxicity and Should be used sparingly as necessary. Forced diuresis is important because
paraquat is a renal tubular toxin.
Glyphosatc, simazine (similar to atrazine), and amitrole are believed to
have low to neglible acute toxicity. Glyphosate has caused transient signs of ocular and
dermal irritation after exposure to recently treated grass; signs resolve quickly when the
product is rinsed from the pet.
Treatment Treatment of 2,4-D poisoning includes activated charcoal and
alkaline diuresis. Paraquat treatment is discussed on 1). 209. Treatment of glyphosate
poisoning would be necessary only in the event the pet drank directly from a concentrated
formulation. Treatment would necessitate gastrointestinal decontamination and activated
charcoal administration. Further treatment would be symptomatic and supportive.
HOUSEHOLD CLEANING PRODUCTS
See also Adds and alkalis, Bleaches, Builders Phenolics, Soaps
General information
Many brands of cleaners are available, and many of these cleaners contain multiple
poisons. Therefore the decision regarding treatment may become complex. In general, treat
the poison that is most toxic.
Surfactants and alkalis may dissolve mucous membranes and cause liquefaction necrosis;
intravascular hemolysis can be seen as well. Alkalis continue to penetrate tissue until
removed or inactivated by deeper tissues. Acids, formaldehyde, phenols, and other
corrosives produce a coagulation necrosis; the coagulum acts as a barrier to further
penetration, making acid injuries less serious than alkali injuries. Phenols may also
produce a penetrating lesion and are .hepato-, neuro-, and nephrotoxi . xalates bind
calciurn. A toxic mechanism has not been discovered for some products, including borates.
Antidote information is commonly found on many household cleaning products. The Poisindex
(Micromedex, Inc., Denver, CO 80204-4506) and Clinical Toxicolqgy of Commercial Products
are handy references.
No attempt should be made to neutralize acids or alkalis by any of the commonly mentioned
"antidotes," such as lenion juice, vinegar, antacids, or bicarbonate; these are
ineffective and may cause further injury by the heat generated by the exothermic
reactions. Water is generally sufficient in attempting to remove or dilute the poison.
HYDROGEN SULFIDE
Sources Hydrogen sulfide is a highly toxic gas that is heavier than
air. It is found in oil wells, refineries, tanneries, sulfur hot springs, hot asphalt
fumes, mines, manure-holding pits, septic tanks, and sludge pools.
Mechanism of action Hydrogen sulfide ions bind to cytochrome
oxiclase within mitochondria, thus blocking electron transport. This blockade results in
cellular asphyxia similar to (but different from) the action of cyanide. It is also
capable of causing direct irritation to mucous membranes.
IBUPROFEN (Motrin, Advil Nuprin, Vick's DayQuil)
NONSTEROIDAL ANTI INFLAMMATORY DRUGS (NSAIDS)
See also Acetaminophen, Aspirin
Sources Many analgesics, antipyrerics, antiinflammatory drugs belong to
this class of drug. txamples include indomethacin, piroxicam (Feldene), ibuprofen (Motrin,
Advil Nuprin, Vick's DayQuil), phenylbutazone (Bute, Butazoliclin): naproxen (Naprosyn,
Aleve).
Mechanism of action NSAIDS inactivate cyclooxygenase and therefore
inhibit production of protective prostaglandins of the E-series. Reduced prostaglandin
production results in reduced blood flow to the Gi tract, reduced secretion of gastric
mucus, and G1 tract ischemia and ulceration (which may perforate). Prostaglandin
inhibition also reduces blood flow to the kidneys resulting in renal papillary necrosis
and acute renal failure. Newer NSAIDS such as carprofcn are touted to have fewer toxic
side effects because of decreased inhibition of prostaglandin synthesis and yet offer
effective antiinflammatory action.
Clinical signs Abdominal pain, lethargy, anemia, melena, and hematemesis
are most commonly seen with G1 irritation and ulceration. if perforation has occurred,
clinical signs may include abdominal pain, perhaps a fluid wave, shock, injected sclera,
brick-red mucous membranes, and tachycardia. Temperature may be elevated or depressed.
Pulses may be bounding or weak and thready.
Clinical signs associated with acute renal failure include hyposthenuria or isosthenuria,
renal tubular cell casts in the urine sediment, or glucosuria without hyperglycemia. Urine
gammaglutamyltransferase erase (GGT) will be elevated. These early signs of acute renal
failure will be followed by increasing BUN and creatinine, electrolyte disturbances, and
possibly oliguria or more rarely polyuria. Occasionally, increased alanine
aminotransferase (ALT) and alkaline phosphatase (ALP) may be seen.
Signs
Abdominal pain Lethargy Anemia Melena, hematochezia Hematemesis Increased BUN and
creatinine Hyposthenuria or isosthenuria Renal tubular casts Glucosuria without
hyperglycernia Increased ALT and ALP Hypoventilation or apnea in some cases Acid-base
disorders (sometimes initial alkalemia with later metabolic acidemia) Signs of peritonitis
if perforation Coma, rarely seizures
Treatment Treatment involves preventing or correcting GI ulceration,
perforation, and acute renal failure. There is no specific antidote for NSAIDs.
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen .
3. Secure venous access. Treat shock if needed. Collect blood and urine
for laboratory testing. Obtain data base including
biochemical profile, electrolytes, venous or arterial
blood gases, and urinalysis.
4. Control seizures if necessary.
5. Insert a urethral catheter and administer crystalloids to maintain
urine output of at least 2 to 3 mL/kg/hour in the dog and 1
to 2 mL/kg/hour in the cat. Rapid development
of oliguria or anuria associated with NSAID overdose dramatically
increases the danger of overhydration. Patients must
be monitored closely. Monitor central venous pressure if possible.
6. Perform serial monitoring of the urine to detect evidence of acute
renal failure.
IF PERFORATION IS SUSPECTED
Confirm with abdominocentesis. Consider diagnostic peritoneal lavage if abdominocentesis
fails to confirm yet suspicion is high. Support the patient and perform exploratory
surgery to repair perforation. Perform thorough abdominal lavage using large quantities of
sterile saline Continue treatment with open abdominal techniques or intermittent abdominal
lavage and active drainage. Provide IV broad-spectrum antibiotics.
IF RENAL DAMAGE IS SUSPECTED BASED ON URINE ANALYSIS Treat acid-base and
electrolyte imbalances: a. Fluid therapy with crystalloids will usually correct the
acid-base problems. If severe acidernia is present (pH <7. 1), administer sodium
bicarbonate. b. Treat hyperkalemia if present. Continue crystalloids to maintain urine
production of at least 2 to 3 mL/kg/hour in the dog and I mL/kg/hour in the cat.
Administer furosemide (Lasix) dopamine, or mannitol, or all three, to maintain urine
production as above. Monitor CVP, blood pressure, and urine output.
Decontaminate
Induce emesis if recent ingestion (2 to 4 hours) or if signs are not present. Gastric
lavage if signs are present after ingestion . Adminster activated charcoal and a saline
cathartic; repeat PRN q4-6h.
Administer antidotes or other indicated supportive care.
a. Protect the GI tract: a. Administer sucralfate.
b. Administer misoprostol (Cytotec) at I to 5 mcg/kg q812h PO (dog only)
for ulcer prophylaxis.
c. Administer omeprazole at 0.7 mg/kg q24h PO dog only.
d. H 2-receptor antagonists have not been shown to be of benefit as a
prophylactic therapy against NSAID-induced G1
ulcers.
Enhancement of elimination
Call the poison control center for advice concerning the specific NSAID in
question.
Avoid
Gentamycin and other nephrotoxic drugs.
References:
Engelhardt J, Brown S: Drug-related nephropathies, Part 2: Commonly used drugs, Compend
Cont Ed Pract Vet 9(3):281-288, 1987.
Gfeller RW, Sandors AD: Naproxen -associated duodenal ulcer complicated by perforation and
bacteria- and barium sulfate-induced peritonitis in a dog, J Am Vet Med Assoc 198
(4):644-646, 199 1.
Kore A: Ibuprofen. In Kirk RW, Bonagura JD, editors: Current veterinary therapy, ed 11,
Philadelphia, 1992, Saunders.
Matz M: Gastrointestinal ulcer therapy. In Bonagura JD, Kirk RW, editors: Current
veterinary therapy, ed 12, Philadelphia, 1992, Saunders.
Murphy M: Toxin exposures in dogs and cats: drugs and household products, JAm VetMed Assoc
205(4):557-560, 1994.
Spyridakis LK, Bacia JJ, Barsanti JA, Brown SA: Ibuprofen toxicosis in a dog, J Am Vet Med
Assoc 189 (8): 918-919, 1986.
Thomas N: Piroxicam -associated gastric ulceration in a dog, Compend Cont Ed Pract Vet
9(10):1004-1030, 1987.
Vasseur PB, Johnson AL, Budsberg SC, et al: Randomized, controlled trial of the efficacy
of carprofen, a nonsteroidal anti-inflammatory drug, in the treatment of osteoarthritis in
dogs, J Am Vet Med Assoc 206(6):807-811, 1995.
ISOPROPANOL (ISOPROPYL ALCOHOL)
LEAD
Sources Lead is found in old paints, some artist's paints, lead toys,
drapery weights, sinkers, solder, wine bottle cork foils, battery plates, golf balls,
improperly glazed ceramic dishes, used motor oil from engines that burn leaded gasoline,
plumbing materials, lineoleum, tile, and lead smelters. The most common route of exposure
is by ingestion, but lead is highly absorbable when heated to release fumes. Lead is
absorbed from inhaled and topical exposure to leaded gasoline. Particulate lead may be
inhaled from the exhaust of engines burning leaded gasoline.
Mechanism of action Lead interferes with metabolic pathways of
hemoglobin synthesis and normal erythrocyte maturation. Erythrocytes become more fragile
and have reduced oxygen-carrying capacity. Ischernia may cause CNS signs. In addition,
high concentrations of lead are known to cause cerebral edema and neuronal damage in the
central nervous system. Peripherally, lead causes nerve demyelination and slower nerve
-conduction velocities.
Clinical signs
Young dogs are most susceptible
NEUROLOGIC SIGNS
Central nervous system
Seizures
Dementia, hysteria
Head pressing
Champing of jaws
Vocalizing
Running aimlessly
Biting at everything
Circling
Compulsive pacing
Peripheral nervous system
Muscle spasms, opisthotonus
Polyneuropathy (chronic lead poisoning)
Quadriparesis
Quadriparalysis
Depressed spinal reflexes
OCULAR SIGNS
Blindness
Mydriasis
Iridocyclitis
Swelling of optic disk
GASTROINTESTINAL SIGNS
Anorexia
Vomiting
Constipation often followed by diarrhea
Apparent abdominal pain
Tucked abdomen
Diagnosis
Complete blood cell count may be normal. Sometimes nucleated RBCs are found in the
peripheral blood without corresponding polychromasia. Occasionally basophilic stippling is
seen in the RBCs. Anemia is found occasionally.
URINE
Urine analysis may be normal or may show renal casts (hyaline or granular). Occasionally,
small amounts of protein and glucose are found because of lead-induced renal damage.
URINE LEAD
Urine lead levels >0.75 ppm are suggestive of lead poisoning. Urine lead levels may be
more accurate if the patient is treated with the chelator calcium disodium
ethylenediaminetetraacetic acid (CaEDTA). A urine lead level is determined before
chelation therapy is begun. CaEDTA is administered (see treatment below) and a 24-hour
urine lead sample is collected. Urine lead levels >0.82 ppm 24 hours after chelation
therapy is begun is diagnostic for lead poisoning.
BLOOD LEAD
Determination of blood lead levels is the most valuable laboratory test. Approximately 90%
of absorbed lead is carried bound to erythrocytes. Therefore analysis must be performed on
whole blood, not serum or plasma. Heparinized or EDTA tubes are submitted. Blood lead
levels >_0.6 ppm are diagnostic; levels >_0.350.6 are considered diagnostic if
accompanied by signs or other ancillary tests (see below). Blood lead levels do not
correspond well with severity of signs. In cases of chronic plumbism, there is reported to
be a high level (30%) of false negatives.
TISSUE LEAD
Liver and kidney lead levels >10 ppm are diagnostic for lead toxicosis. Some
toxicologists consider lower levels and supportive signs to be conclusive for plumbism.
FECAL LEAD Levels >35 ppm are suggestive.
RADIOGRAPHS
Metallic foreign bodies help support the possibility of lead poisoning; however, negative
radiographic findings do not rule out lead poisoning. Rarely, radiographs of the
epiphyseal plates (in dogs) reveal a 'lead line.
Serum aminolevulinic acid (ALA) dehydratase inhibition and zinc protoporphyrin levels are
sensitive tests but are expensive and do not replace blood lead in value.
EMERGENCY TREATMENT
Procedures
I . Secure the airway and assist ventilation if necessary (pp.
2. Secure venous access (p. 16).
3. Control seizures (p.
4. Treat cerebral edema as necessary based on signs or CSF
analysis that reveals cerebral inflammation. (See p. 29
for increased intracranial pressure.)
a. Furosemide (I to 5 mg/kg IV) followed by
b.Mannitol (0.1 to 1.0 g/kg IV over 15 to 30 min-
utes)
c. Corticosteroids
Methylprednisolone sodium succinate (25 to 30
mg/kg IV at entry followed by 12.5 to 15 mg/kg
IV at 2 and 6 hours after entry; then 2.5
mg/kg/hour IV continuous infusion for 8 to 42
hours)
Dexamethasone sodium phosphate (2 to 3 mg/kg
IV followed by I mg/kg SC q6-8h in tapering
doses)
Decontaminate
I . Locate source and prevent further exposure.
2. Remove lead foreign bodies if present in G1 tract or synovial spaces.
Lead bullets Or shot lodged in tissue are not usually associated with lead poisoning. They
should, however, be removed if no other source of lead can be found in a patient with
elevated blood lead levels and supportive signs.
3. Endoscopy
4. Surgery
5. Gastric lavage (not highly successful)
6. Catharsis with sodium sulfate or magnesium sulfate (0.5 mg/kg in a
10% solution in water by stomach tube). Not only does this promote evacuation of
gastrointestinal foreign bodies, it also results in formation of a poorly absorbed lead
salt (lead sulfate).
Section two: Toxic drugs and chemicals 177
Administer antidotes and other supportive care
BEGIN CHELATION THERAPY
Succirner (meso-2,3-dimercaptosuccinic acid, or DMSA) and 2,3-dimercapto- I
-propanesulfonic acid, sodium salt (or DMPS) are newer chelators that show promise.
Succimer (Chemet, McNeil Consumer Products Co., Fort Washington, PA 19034) has recently
been made available in the USA, but DMPS is not yet available in this country. Succimer
administered orally at 10 mglkg q8h for 10 days has been found to successfully eliminate
clinical signs of plumbism. It is believed to be less toxic than dimercaprol, calcium
EDTA, or penicillamine. Administer dimercaprol (BAL). CaEDTA will increase lead excretion
20- to 50-fold. Occasionally this will make the patient worse. Administration of
dimercaprol first may lessen this effect, Administer 10% dimercaprol in oil (2.5 mg/kg IM
q4h on days I and 2, q8h on day 3 and then q 12 h). The dose may be increased to 5 mg/kg
on day I only in acute, severe cases. Administer CaEDTA (25 mg/kg diluted to a
concentration of 10 mg/mL in 5 % dextrose in water given SC q6h for 5 days). CaEDTA may be
nephrotoxic. Do not exceed 5 days of continuous therapy. Do not exceed a 2 g total daily
dose. Administer penicillamine. Penicillamine (8 mg/kg PO q6h or 10 to 55 mg/kg ql2h) may
be administered orally in place of CaEDTA. It should be given on an empty stomach but may
cause vomiting. Antiernetics may help resolve this complication.
ADMINISTER THIAMINE
I to 2 mg/kg IM or 2 mg/kg PO q24h
ADMINISTER BROAD-SPECTRUM ANTIBIOTICS
Lead may be immunosuppressive.
CONTINUE THERAPY UNTIL BLOOD LEAD LEVELS ARENORMAL If lead poisoning is
diagnosed early, before signs are severe or chronic, the prognosis for recovery is good.
Even patients suffering polyneuropathy may fully recover. if the signs are severe, or CSF
analysis is abnormal, full recovery is not so likely, but the patient may still recover to
an acceptable state.
(+)-LIMONENE,
LINALOOL, CRUDE CITRUS OIL EXTRACTS
Sources Insecticide, insect repellent, food additive, fragrance.
Mechanism of action The mechanism of action of the citrus oil extracts
has not been fully elucidated. It appears that both central and peripheral vasodilatation
take place upon exposure. Linalool has a more prolonged action.
Clinical signs Signs associated with toxicity of the crude citrus oil
extracts include almost immediate hypersalivation, muscle tremors, ataxia, depression, and
hypothermia. Although it appears that (+)-limonene has a wide margin of safety compared
with linalool of other citrus oil extract, improper calculation of the dilution or
careless use of the undiluted product has resulted in pronounced toxicosis. Most cats will
recover in a matter of 6 to 12 hours, provided that the toxicosis was caused by
(+)-limonene as the sole toxic agent. When other crude citrus oil extracts are the cause,
the signs may be prolonged. Deaths have been reported.
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine [or laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure and perfusion.
5. Control seizures.
6. Treat hypothermia if present.
Decontaminate
Bathe the cat in liquid dishwashing detergent. Continue lot at least 15 minutes or until
the odor is gone. Keel) the patient in a warm, well-ventilated area. induce emesis only if
the ingestion was within the last 10 minutes and the patient shows no clinical signs.
Perform gastric lavage if the ingestion was within the last 2 to
4 hours.
Give repeated doses of activated charcoal.
Administer saline cathartic. Magnesium-containing solutions
should be avoided.
Consider whole-bowel irrigation using CoLyte or GoLYTELY.
Avoid
Atropine is not indicated for plyalism associated with this toxicity.
LIME (QUICKLIME)
Clinical signs:
Lime produces heat and may burn and severly and irritate the skin.
Treatment
:Flush the skin with plenty of water. If the skin is burned, seek vetinary care
immediately.
LOCAL ANESTHETICS
Sources Creams for teething (Anbesol), cold sores, and
hemorrhoids, sore throat sprays and lozenges (Vicks, Chloraseptic),
benzocaine-containing suppositories, analgesic creams (Lanacane), and
first-aid sprays, topical anesthetics (lidocaine, tetracaine, benzocaine).
Mechanism of action A large amount of these products would need to be
ingested to produce significant toxic effects
for compounds containing lidocaine. However, methemoglobinernia, which can occur after
oxidation of hemoglobin, is possible with topical application of even a small amount of
benzocaine and tetracaine products; the cat is especially sensitive.
Clinical signs Signs of methemoglobinemia include cyanosis, open-mouth
breathing, convulsions, and dark brown blood.
EMERGENCY TREATMENT
Procedures
1 . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for labora-
tory testing.
4. Administer isotonic crystalloids as needed to support
blood pressure and perfusion.
5. Treat methemoglobinernia if present.
6. Treat hyperthermia if present.
Decontaminate
INGESTION
induce emesis only if the ingestion was within the last 60 minutes and the patient shows
no clinical signs. Perform gastric lavage if the ingestion was within the last 2 to 4
hours. Give repeated doses of activated charcoal. Administer cathartic.
DERMAL EXPOSURE
Wash thoroughly with warm, soapy water. Avoid chilling the patient.
Administer antidotes or other indicated supportive care
Antidotes for methemoglobinemia include ascorbic acid and
methylene blue which can cause Heinz-Body hernolytic anernia.
Enhancement of elimination
Hyperbaric oxygen is useful if available. Exchange transfusions.
Avoid
Handling. Keep manipulation and stress to a minimum. These patients may be extremely
hypoxemic and therefore quite fragile.
LUBRICANTS
Clinical signs:
Depression, weakness and vomiting, staggering, seizures, paralysis, coma and death may follow.
Treatment:Clean skin and coat with ivory soap or other mild detergent. Induce emisis and pump the stomach. IV fluids, medications to control seizures and general supportive care are all important.
Clinical signs:
Irritation of the mouth, eyes, nose and face with heavy salivation and sometimes vomiting.
Treatment:Flush all exposed areas well. Anti-inflammatory medication and antihistamines may relieve the irritation.
MARIJUANA (Cannabis sativa)
Clinical signs:
Signs vary with how much of the drug is eaten. Behavioral changes, sleepiness, depression, staggering, dilated pupils and a rapid heartbeat all can occur. A slow heart beat, salivation and poor vision have also been reported.
Treatment:In cases of recent ingestion of marijuana, vomiting may be induced if indicated. Activated charcoal may be given. Further treatment is supportive and based on signs.
MERCURY VERY TOXIC
Clinical signs:
Signs occur after ingestion of contaminated fish and include paralysis and/or rigidity of the hindlegs, a stiff, stilted gait, tremors, and convulsions. Symptoms often occur after a period of continued exposure and or injestion.
Treatment:No known treatment, supportive care should be provided. BAL may be helpful.
Sources:
Common ingredient in molluscicides (snail or slug bait), which are available in kibbled, granular, powder, or liquid form. Be aware that baits may contain other toxins. Metaldehyde may also be present in fuels used in small heaters.
Clinical signs:
Signs usually begin showing within 15 minutes to 3 hours after ingestion.
Early Signs
Increased heart and respiratory rates, anxiety, elevated body temperature, muscle tremors, salivation and spasms.loss of coordination.
Fever, vomiting and diarrhea have also been reported. Death as a result of respiratory failure.
Treatment:Pumping the stomach early and giving bicarb can stop absorption. Most cats need to be put on IV fluids and anesthetized or given muscle relaxants to control spasms. Once the stomach is pumped, Pepto-Bismol is used to coat the GI tract, and bicarbonate is given intravenously. If the patient can be maintained for up to 72 hours then survival is possible.
Clinical signs:
When ingested or given by a veterinarian the pupils will become quite small, the cat will breathe slowly, become depressed or highly sedated and can die.
Treatment:
IV fluids to flush the system, artificial respiration with oxygen, atropine to speed the heart and nalorphine to counteract the effects of the drug directly. This plus general supportive care will help most patients.
Sources Naphthalene is the active ingredient in old-fashioned mothballs, moth cakes, and moth crystals. it has also been used in toilet bowl deodorizers, The use of naphthalene has largely been replaced with paradichlorobenzene because naphthalene is at least 2 times more toxic than paradichlorobenzene. Naphthalene appears to be quite toxic to cats.
Mechanism of action Naphthalene induces gastrointestinal upset and vomiting. It also is known to stimulate the central nervous system. Hemolysis (from Heinz body anemia) is seen, especially in patients with glucose-6-phosphate dehydrogenase deficiencies,
Clinical findings
Rarely, signs of hepatitis, which occur 3 to 5 days after ingestion
of naphthalene.
Laboratory findings
Complete blood cell count most often reveals hemolytic anemia.
Dehydration as a result of vomiting may offset the reduction of packed cell volume seen
with mild anemia.
Urine analysis may reveal hemoglobinuria.
Usually based on history of ingestion or typical odor of moth balls (patient breath, around mouth, in vomitus). There is no specific test for serum levels of naphthalene.
EMERGENCY TREATMENT
Procedures
1. Secure airway and support ventilation if required.
2. Secure venous access.
3. Control seizures.
4. If anemia is causing signs of hypoxia, administer supplemental oxygen and give red blood cell transfusion.
5. Treat methemoglobinemia if suspected (mucous membranes are dark blue or brown).
6. Treat hemolysis or hemoglobinuria with intravenous crystalloids for
hydration and consider alkalinization of the urine to
prevent precipitation of hemoglobin in the
kidneys.
Decontaminate
Clinical signs:
Ingestion of grains or food contaminated with these fungal toxins can lead to poisoning. Usually this is not much of a problem for cats. Signs include loss of appetite, diarrhea, weakness, vomiting and collapse.
Treatment:
Strict rest and high quality food for 30 days, symptomatic care and fluid therapy as needed.
Clinical signs:
Most cats will salivate and vomit, become depressed, have diarrhea, seizures and bloody urine and can develop hemolytic anemia.
Treatment:
Vomiting should be induced early after ingestion, or pumping the stomach followed by activated charcoal being administered. Saline laxatives and egg whites can be used to protect and clean the digestive tract. IV fluids help to flush the system, and cats may need general treatment for the hemolytic anemia.
Clinical signs:
After ingestion cats will salivate, vomit, have diarrhea and abdominal pain. Later, and depending on dosage, cats become weak, their muscles will twitch, seizures, hypothermia and death can all occur.
Treatment:
Vomiting should be induced early, followed by pumping and flushing the stomach and instilling activated charcoal. IV fluids and general supportive care is needed until all signs have passed. Oxygen and other medications are needed in more extreme cases.
Clinical signs:
Loss of balance and staggering, vomiting, difficulty breathing and blueness to the gums followed by convulsions, coma and death.
Treatment:
Vomiting should be induced followed by giving activated charcoal, oxygen therapy, IV fluids to maintain kidney function, laxatives to clear the GI system, and other medications and specific antidotes.
ONION Any Form - (i.e., raw, cooked,
dehydrated, and powdered)
Onions are extremely toxic to cats because cats
have oxidant-sensitive hemoglobin.
Mechanism of action The active ingredient in oil of onion is allyl propyl disulfide; the active ingredient in oil of garlic is a similar compound called "allicin." Onions act as oxidizing agents that cause Heinz body anemia. Garlic appears to he safe, but anemia has been observed in chronic toxicity studies. Garlic may cause contact dermatitis or imitate an asthmatic attack.
Clinical signs Signs are secondary to anemia and include pale mucous membranes, tachycardia, tachypnea, lethargy, and weakness. Vomiting, diarrhea, and hematuria or hemoglobinuria secondary to intravascular hemolysis can be seen. Microscopically, Heinz bodies, leptocytes, and poikilocytes may be observed.
Treatment No specific antidote exists. Treatment is supportive and is an attempt to reduce the oxidative effects of the active ingredient and prevent renal damage caused by hemoglobinuria.
EMERGENCY TREATMENT
Procedures
1. . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure and perfusion. 5. Perform type and major and minor crossmatch and administer fresh, whole blood, stored blood, packed red blood cells if Induce emesis if the ingestion was within the last 60 minutes and the patient shows no clinical signs.
Perform gastric lavage if the ingestion was within the last 2 to 4 hours.
Administer saline cathartic.
Administer antidotes or other indicated supportive care
1 . Administer crystalloid fluids to induce brisk diuresis to avoid renal damage caused
by hemoglobinuria. Monitor
urine output and central venous pressure.
2. Monitor blood gases and urine pH. It is imperative that acidic urine not be allowed
because acidic urine will promote renal
damage from hemoglobinuria. Correct with sodium
bicarbonate as needed.
Enhancement of elimination
There are no known effective measures.
Avoid
Many baby foods are reported to contain onion. Avoid feeding these baby foods to recovering patients.
ORGANOPHOSPHATES and CARBAMATES (ACUTE POISONING)
Sources Malathion, parathion, Diazinon, carbaryl (Sevin), bendiocarb (Ficam), propoxur (Baygon, Sendran), chlorpyrifos(Dursban), methylcarbamate, chlorfenvinphos (Dermaton Dip), cythioate (Proban), dichlorvos (Vapona), dioxathion,fenthion (ProSpot), runnel, phosmet, disulfoton (Di-Syston), Golden Malrin (fly bait).
Mechanism of action Acetylcholine is utilized as a neuro- transmitter in many nerve junctions. in the normal animal, acetylcholine is quickly inactivated by acetylcholineste rase and pseudocholinesterase. Organ oph osphate s and organocarbamates competitively inhibit acetylcholinesterase and pseudocholinesterase allowing the continued presence of acetylcholine to maintain a constant state of nerve stimulation. Acetylcholinesterase inhibition by organophosphates tends tobe irreversible; inhibition by organocarbarnates tends to be reversible. Organ ophosph ates and carbarnates are readily absorbed from the skin and the G1 tract and by inhalation.
Clinical signs Signs may be muscarinic, nicotinic, or generalized CNS signs; usually a combination of signs are seen, Muscarinic signs include dyspnea (caused by bronchorrhea and bronchoconstriction), excessive lacrimation, salivation, miosis, micturition (urination), and defecation. Bradycardia is often seen, but tachycardia resulting from catecholarnine release may be seen. Nicotinic signs include twitching of facial muscles, tremors, generalized muscle fasciculations, and then weakness and eventually paralysis. Signs referrable to the CNS include convulsions, seizures, ataxia, and anxiety; centrally mediated respiratory depression may lead to respiratory failure and death. Depression or aggression may be seen.
Diagnosis History, exposure to toxin, and blood cholinesterase depression are useful in the diagnosis of organophosphate or organocarbamate poisoning. Blood (not plasma) cholinesterase depression of 50% of normal (or more) indicates exposure. Depression of cholinesterase activity to less than 25% of normal are often seen in toxicitics. Levels may remain depressed for several days to several weeks; some depression is normal after exposure to routine application of insecticides. Although not a definitive test, an atropine trial may be useful Administer atropine IV at 0.02 to 0.04 mg/kg. If signs of atropinization occur (tachycardia, dry mouth, mydriasis), there is little likelihood that the pet has been poisoned by a cholinesterase inhibitor.
Treatment Atropine is antidotal for carbamates and organophosphates and relieves muscarinic signs. Nicotinic signs can be controlled with diphenhydramine hydrochloride and sedatives such as diazepam. Pralidoxime (2-PAM) will reactivate cholinesterase by freeing the active part of the alkylphosphorylated enzyme complex. 2-PAM has been reported to be of no benefit in treating carbamate toxicosis and may actually further inhibit cholinesterase; however, this report is now disputed. Most recent literature indicates that, if it is uncertain what the toxin is but signs suggest a cholinesterase inhibitor, the use of 2 -PAM is indicated. If no response is seen within 3 or 4 doses, the value of the drug is minimal and it is discontinued. 2-PAM should be given early (within 24 hours) in the course of treatment to prevent "aging" of the enzyme complex. Acidosis is treated with fluid therapy and bicarbonate as needed. Emesis and gastric lavage are indicated if oral ingestion occurred (drinking the toxin or licking the toxin from the coat).
Clinical Signs
MUSCARINIC
SLUD (salivation, lacrimation, urination, defecation), vomiting, dyspnea, bradycardia
NICOTINIC
Muscle fasciculations and then weakness or paralysis, ataxia.
CNS
Convulsions, ataxia, anxiety, respiratory depression or failure, death.
NOTE: Cats that have been poisoned with chlorpyrifos often have lethargy or weakness as the only sign. Blood cholinesterase or plasma pseudocholinesterase levels may be valuable in differentiating intoxication with chlorpyrifos from other causes of lethargy and weakness in cats.
EMERGENCY TREATMENT
Procedures
I . Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure and perfusion.
5. Control seizures.
6. Treat hyperthermia if present.
Decontaminate
INGESTION
Induce emesis only if the ingestion was within the last 60 minutes and the patient shows no clinical signs.
Perform gastric lavage if indicated.
Give repeated doses of activated charcoal.
Administer saline cathartic, if necessary. This is usually
not necessary because these patients often have diarrhea already
caused by the toxin. Magnesium -containing
cathartics should be avoided if CNS signs are present.
DERMAL EXPOSURE
Wash thoroughly with warm, soapy water. Wear rubber gloves when bathing the patient. Avoid induction of hypothermia.
Oral administration of activated charcoal is indicated in dermal exposure.
Administer antidotes or other indicated supportive care
1. Atropine sulfate 0.2 to 2.0 mg/kg (give 1/4 dose IV,
remainder IM or SQ). In cases of severe dyspnea associated with
OP or OC toxicity, it is important to administer oxygen before
administration of atropine. Failure to do so may result in
tachycardia in a patient who cannot meet the demands of increased
myocardial oxygen consumption. Repeat atropine
frequently in decreasing dosages (approximately half the initial
dose) as needed. Although the decision to repeat has often
been based on the presence or absence of salivation or miosis,
this is not appropriate. The clinical decision to repeat
atropine should be based on reappearance or persistence of respiratory
signs (wheezing, bronchorrhea, dyspnea). Atropme
effects usually last for 4 to 6 hours. Avoid overdosage.
2. Pralidoxime chloride (2-PAM) 20 to 50 mg/kg IV slowly or SC q12h. Start with
lower dose. If no response after 3 or 4
doses, discontinue 2-PAM therapy.
3. Diphenhydramine 1 to 4 mg/kg IM, PO q8h to relieve
muscle tremors (nicotinic signs); start with lower dose when giving
IM.
4. Treat acidosis as needed, preferably based on blood gases.
Enhancement of elimination
There are no known effective techniques.
Avoid
Morphine, succinylcholine, phenothiazine tranquilizers, and any drugs that decrease the respiratory drive are contraindicated. Other drugs that are contraindicated include procaine, anything with magnesium, inhaled anesthetics, depolarizing neuromuscular- blocking agents, aminoglycoside antibiotics, clindamycin, lincomycin, polymixin A and B, colistin, cimetadine, theophylline, and theophylline- ethylenediarnine.
References:
Fikes JD: Toxicology of selected pesticides, drugs and chemicals: organophosphorus and carbamate insecticides, Vet Clin North Am Small AnimPract20(2):353-367, 1990.
Jaggy A, Oliver JE: Chlorpyrifos toxicosis in two cats, J Vet Intern Med 4(3):135-139, 1990.
Miller E: Organophosphate toxicity in domestic animals-1: acute toxicity, VetMed Small Anim Clin 78:482-488, 1983.
Murphy MJ: Toxin exposures in dogs and cats: pesticides and biotoxins, J Am Vet Med Assoc 205 (3):414-421, 1994.
Clinical signs:
Ulcers of the mouth with salivation, swelling of the larynx, vomiting with blood, diarrhea, dehydration, dilated pupils, muscle twitching, collapse and death.
Treatment:
Oral calcium lactate, egg whites or olive oil all can be given as protectants. Pumping the stomach and flushing the stomach with lime water, magnesium sulfate orally, respiratory support, oxygen, IV fluids and bicarbonate are all important.
Alcohol, essential oils (e.g., savin, rue, tansy, apiol, juniper, cedar leaf, cajupute)
Clinical signs:
Essential oils are often hepatotoxic (Liver) or nephrotoxic Kidney) and may irritate the skin, mucous membranes, and lungs, resulting in aspiration, pulmonary edema, and pneurnonitis; albuminuria, hematuria, and glycosuria result from renal damage- CNS effects include excitement, ataxia, disorientation, and coma; odor of volatile oils may be present in expired air or in vomitus Irritation of eyes, nose and mouth will occur. Vomiting, diarrhea, salivation, restlessness, staggering, coma and death can occur.
Treatment:
Wash all exposed areas with water. Induce vomiting then pump and flush the stomach. IV fluids, anti-vomiting medications and supportive care are all important.
Because of the possibility of aspiration pneumonia from volatile hydrocarbons, gastric lavage and emesis should be used cautiously
Clinical signs:
Vomiting, diarrhea, difficulty breathing, shock, depression, coma and death. Aspiration pneumonia is common and often greatly complicates recovery.
Treatment:
Vomiting generally should NOT be induced. Vegetable oils to coat the stomach are useful. Oxygen therapy, IV fluids and general supportive care are all important to save the patient.
PHENOLS and CRESOLS (Lysol)
Sources Phenol and phenolic compounds are coal-tar derivatives
found in disinfectants, drugs and foods (benzoic acid), caustics (phenol), keratolytics
(phenol and resorcinol), soaps (3% hexachlorophene, pHisoHex), and antiseborrheic shampoos
and other products (phenol and coal tar).
Mechanism of action Phenols denature and precipitate proteins of
all cells. They are extremely corrosive and produce penetrating lesions. In lower doses,
phenols and phenolic Compounds cause direct stimulation of the respiratory center of the
brain. The result is hyperventilation and respiratory alkalosis. Metabolic compensation
for the respiratory alkalosis results in renal excretion of bicarbonate. The phenols are
mildly acidic and disrupt carbohydrate metabolism. The respiratory alkalosis is followed
by metabolic acidosis. Phenols are absorbed rapidly from the G1 tract as well as
percutaneously. Cats, certain reptiles, and birds are highly sensitive to phenols.
Phenolics are caustic to mucous membranes, causing visible corrosion. Most pets will not
ingest enough product to cause esophageal injuries. Cutaneous exposure with concentrated
products results in corrosive injury that is initially white in color followed by the
development of dry dermal eschar formation. Severe corneal injury including ulceration and
penetration result from contact with phenolic compounds. Hexachlorophene causes
demyelination and spongiosis of white matter.
Clinical Signs Profuse ptyalism, anorexia, emesis, panting, and ataxia
are seen. As time progresses, muscle fasciculations, shock, and unconsciousness may
develop. Mucous membranes may be dark because of respiratory depression and
methenioglobineniia. Hepatic and renal damage are seen within 12 to 24 hours.
Toxicity with hexachlorophene is most commonly seen in young puppies and kittens bathed
with pHisoHex. This product is slightly water insoluble and remains on the skin after
bathing, which allows skin penetration. Signs of hexachlorophene toxicity include
weakness, trembling, lethargy, shock, muscle tremors, hypothermia, tachycardia, tachypnea.
Excretion of phenolic metabolites may discolor the urine green or black; addition of
ferric chloride to the urine turns it
purple or blue.
Treatment Phenolic intoxications are true emergencies. Owners
should be instructed to administer water, milk, or egg whites before transport to the
veterinary hospital. Emesis should not be induced nor should gastric lavage be attempted
if esophageal injury is suspected. Otherwise gastric lavage and activated charcoal are the
treatment of choice. N-Acetylcysteine (Mucomyst) may prevent renal and hepatic injury.
Ascorbic acid or methylene blue is used to correct methemoglobinemia. Respiratory
alkalosis followed by metabolic acidosis is often seen and treated as needed; oxygen is
given as necessary. Exposed skin should be washed with soap and water.
Neurologic signs seen in experimental hexachlorophene poisoning in cats were treated with
30% urea and resulted in a rapid decrease in CSF pressure; cats did not respond to
treatment with prednisolone or acetazolamide. Experimentally, adult cats given 20
mg/kg/day developed neurologic signs within 2 weeks of daily administration; paralyzed
cats that did not develop corna completely recovered within 4 to 6 weeks after treatment
with urea and supportive care.
Signs
Profuse salivation
Anorexia
Emesis
Panting
Respiratory stimulation followed by depression
Ataxia
Muscle fasciculations
Shock
Unconsciousness
Dark mucous membranes
Green or black urine
EMERGENCY TREATMENT
Procedures
I . Carefully secure the airway and ventilate as necessary
.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure
and perfusion.
5. Treat methemoglobinemia if present.
6. Treat hyperthermia if present.
Decontaminate
INGESTION
DERMAL EXPOSURE
OCULAR EXPOSURE
Administer antidotes or other indicated supportive care
Mucomyst may be indicated to help avoid renal and hepatic damage.
Enhancement of elimination
There are no known effective techniques.
PINE OILS
Sources Sanitizers, disinfeclants.
Mechanism of action The lethal dose for small mammals is estimated
at 1.0 to 2.5 mL/kg; a lower dose can result in severe intoxication. Pine oils are
directly irritating to mucous membranes. They are readily absorbed from the GI tract
resulting in severe gastrointestinal signs. Renal cortical damage and CNS depression also
occur.
Clinical signs The odor of pine oil is often present; pronounced
oral and pharyngeal irritation are usually seen. Vomiting, retching, progressive CNS signs
including hyperesthesia, weakness, ataxia, and coma occur. Tachycardia, hyperthermia, and
nephritis occur as well. Vomiting usually occurs after ingestion. Pulmonary damage results
from aspiration or chemical pneumonia from absorption of pine oil frorn the GI tract and
subsequent deposition in the lung.
Treatment owners should be advised to promptly administer water, milk, or
egg whites. The patient should be transported to the hospital where it should be
hospitalized and observed closely for at least 24 hours. Since aspiration pneumonia is a
real danger and the onset of CNS depression can be rapid, induction of emesis is
contraindicated (though nearly all patients will vomit after ingestion because of the
irritating nature of pine oils). Gastric lavage may be a feasible treatment option but
must be weighed against the risk of causing aspiration pneumonia. Activated charcoal and
cathartics are given. Maintaining fluid and electrolyte balances is essential.
Signs
Pine oil odor
Pronounced oral and pharyngeal irritation
Retching, vomiting, hematemesis
Hyperesthesia
Pulmonary edema, dyspnea, tachypnea
Pneumonia
Severe CNS depression
Weakness
Ataxia
Tachycardia
Hyperthermia
Unresponsive pupils
Coma
Death
EMERGENCY TREATMENT
Procedures
1. Secure the airway and ventilate as necessary.
2. Administer supplemental oxygen.
3. Secure venous access. Collect blood and urine for laboratory testing.
4. Administer isotonic crystalloids as needed to support blood pressure
and perfusion.
5. Treat pulmonary edema if present.
6. Control seizures.
7. Treat hyperthermia if present.
Docontaminate
INGESTION
DERMAL EXPOSURE
Bathe thoroughly with soap and water. Rinse well.
OCULAR EXPOSURE
The eye should be irrigated with copious quantities of sterile isothermic isotonic saline
or water for 20 to 30 minutes.
Ocular damage should be treated using generally accepted treatment options.
Administer antidotes or other indicated supportive care
There are no known antidotes.
Enhancement of elimination
Resin hemoperfusion is most effective followed by charcoal
hemoperfusion. Hemodialysis is minimally effective.
PHOSPHORUS
Clinical signs:
Vomiting and diarrhea with a garlic odor to the breath and vomitus, abdominal pain, bleeding, shock and death all occur.
Treatment:
Vomiting should be induced if possible, followed by pumping and flushing the stomach and administering medication to neutralize the phosphorus, and mineral oil to coat the stomach. IV dextrose is also useful in most patients.
Clinical signs:
Vomiting with bleeding, weakness, depression, respiratory failure and death. Odor of pine is often obvious.
Treatment:
Pumping and flushing the stomach if possible, IV fluid therapy and general supportive care.
PYRETHRINS and PIPERONYL BUTOXIDE
Clinical signs:
Relatively non-toxic in cats but can cause skin irritation, salivation, vomiting, diarrhea, staggering, excitation, seizures and lead to death of the cat.
Treatment:
Wash from skin, pump the stomach if early. Give IV fluids and general supportive care.
Fluids, electrolytes, atropine and diazepam are quite useful in treatment of this toxicity.
Clinical signs:
Oral and stomach pain, weakness, trouble breathing, shock and blue gums all occur.
Treatment:
Induce vomiting if early enough followed by flushing the stomach with milk or lightly soapy water. Egg whites and more milk to soothe the GI tract, anti seizure medications and oxygen therapy or IV fluids in cases where shock and collapse have occurred.
Clinical signs:
Externally, rotenone irritates the skin, eyes, nose and throat.
Internally, rotenone causes vomiting, general gastrointestinal upset, depression and seizures.
Treatment:
Wash with large quantities of water. Induce vomiting as early as possible, then pump and flush the stomach. IV fluids and general supportive care should pull most cats through.
Clinical signs:
Light duty soaps are least toxic, soaps for use in machines can be quite toxic. Nausea, vomiting, diarrhea, difficulty breathing and weakness can all occur. Stronger soaps may cause staggering, depression, seizures, shock and death.
Treatment:
Always induce vomiting if within 2 hours of ingestion. Give milk or olive oil, IV fluids containing calcium. With the more toxic detergents flush and pump the stomach, give oxygen therapy and treat for a blocked trachea or fluid in the lungs.
Species Latrodectus (female black and red widows) and Loxosceles (brown recluse).
Mechanism of action:
Latrodectus spp. release a neurotoxin that is toxic to presynaptic nerve processes, which causes an increase of calcium ions. This locks open ion-exchange channels; thus the release of acetylcholine and norepinephrine is promoted. The toxicity of the bite is highest in autumn, lowest in spring. The amount of venom injected is variable; 15% of bites contain no venom.
Loxosceles spp. release a dermonecrotic toxin as well as several proteins that have direct toxic effects on erythrocytes.
Clinical signs
Latrodectus bites result in regional tenderness and numbness followed by hyperesthesia. Muscle pain (often severe) and fasciculations with cramping of the muscles of the chest, abdomen, lumbar area, and other large muscle groups occurs. Abdominal rigidity without tenderness is a classic sign of envenomation by the black widow spider. Spasmlike activity and possibly seizures can be noted. Respiration may be compromised because of abdominal cramping. Motor signs may abate within 10 to 20 hours after envenomation and may be followed by flaccid paralysis. Hypertension and tachycardia may be seen. Death is caused by respiratory or cardiovascular collapse. Cats are extremely sensitive to Latrodectus bites: severe pain, salivation, restlessness, and early and pronounced paralysis are seen. Death is common.
Loxosceles bites are initially not painful. If envenomation occurred, the cutaneous form (characterized by localized pain and erythema) is seen within 2 to 6 hours. A bleb or blister is seen within 12 hours of the bite; this lesion often evolves into the classic "bull's-eye" lesion (a dark necrotic center bordered by a white ischemic ring on an erythematous background). Dermal necrosis follows ischemia; focal ulceration occurs within 7 to 14 days. The viscerocutaneous form (characterized by fever, arthralgia, weakness, emesis, convulsive seizures, hemolysis, hemoglobinuria, thrombocytopenia, and potentially acute renal failure) rarely occurs with Loxosceles bites but warrants careful monitoring. Dermal healing is extremely slow, often taking from 8 weeks to many months after the bite; permanent scarring often results.
Treatment
Latrodectus bites are treated with analgesics for pain, calcium for control of muscular signs, antibiotics, and antivenin.Loxosceles bites are treated with excision of the affected tissue and antibiotics and observation for signs of the viscerocutaneous form of reaction.
Signs
Latrodectus bites
Salivation
Loxosceles bites
Localized pain (mild to moderate)
EMERGENCY TREATMENT
Procedures
Administer antidotes or other indicated treatments
Latrodectus
Loxosceles
Avoid
Acidosis, especially in the presence of hemoglobinuria.
References
Bailey EM Jr, Garland T: Toxicologic Emergencies. In Murtaugh RJ, Kaplan PM, editors: Veterinary emergency and critical care medicine, St. Louis, 1992, Mosby.
Peterson M, Meerdink G: Bites and stings of venomous animals. Current veterinary therapy, ed 10, Philadelphia, 1989, Saunders.
Clinical signs:
Cats who ingest strychnine today have most often had the poison given to them on purpose. They will have dilated eyes, trouble breathing, blue gums, and what is known as a tonic convulsion with legs out strait and rigid. Seizures can be stimulated or made worse by touch or noise. Respiratory failure and death can occur.
Treatment:
If early, induce vomiting. Pump the stomach and flush with medications and activated charcoal. Most cats are put on IV fluids and given strong sedatives and/or anti seizure medications until seizure activity stops and the body has been rid of the toxin. Some cats will even need oxygen and artificial respiration for a time.
Clinical signs:
Small doses can be lethal, and cumulative toxicity is possible. In these situations clinical signs may include skin changes, hair loss, and ulcers or sores of the lips, anus and genitals. In more severe sudden poisonings, cats may have diarrhea, vomiting, heavy salivation, weakness, trouble breathing, ulcers on the lips (inside), staggering, blue gums, paralysis, seizures and death.
Treatment:
For extreme cases, early pumping of the stomach and giving activated charcoal and potassium for several days is advised. Prussian blue dye may be antidotal. IV fluids, dialysis, bicarbonate and other drugs are all helpful. The worse the signs, the less likely to save the cat.
Clinical signs:
Loss of appetite, weakness, salivation, staggering, spasms, trouble breathing, collapse and death. Poisoning with this chemical is rare in cats.
Treatment:
Flush skin and mouth, flush and pump the stomach, IV fluids to flush the kidneys is important.
Clinical signs:
The smell of turpentine should be the first clue, with abdominal pain, vomiting, diarrhea, excitement or coma and respiratory failure all possible. Severe eye and skin irritation may also be present.
Treatment:
Vomiting generally should NOT be induced. Vegetable oils to coat the stomach are useful. Oxygen therapy, IV fluids and general supportive care are all important to save the patient.
Clinical signs:
Vomiting with abdominal pain is most common, dilated pupils, loss of appetite, tremors, coma, shock and death all occur. Poisoning is rare but the chemical is very toxic to cats.
Treatment:
Pump and flush the stomach as early as possible. IV fluids and nicotinamide therapy are all needed to save these cats.
Clinical signs:
Signs depend heavily on dose and over what period of time that dose is ingested. Depression, internal and external hemorrhages, weakness, fever, shock, trouble breathing, and death all occur. Some cats may have lameness or neurologic symptoms depending upon where hemorrhages occur. Cats may be found dead without clinical signs.
Treatment:
Blood and fluids given intravenously are important, vitamin K1 injections and orally is usually administered to even minor cases.
Clinical signs:
Extreme restlessness, irritability, rapid heart rate, drinking lots of water, vomiting, tense muscles and muscle tremors, seizures and death.
Treatment:
Induce vomiting as early as possible. Pump the stomach and give cathartics to empty the bowels. In more extreme cases oxygen therapy, IV fluids to flush the system, anti-seizure medications and sedatives to control seizures will be needed. Most cats recover in 24-48 hours.
Clinical signs:
Vomiting, diarrhea, abdominal pain, and an unusual odor to the breath and vomitus may be noted. Trouble breathing and fluid in the lungs occurs later followed by weakness, staggering, convulsions and death.
Treatment:
There is no specific treatment. Causing vomiting, pump and flush the stomach, administer oxygen, give IV fluids and medicine to control fluid build-up in the lungs, and other medications to combat the symptoms of the poisoning.
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