Max's House

Ernest E. Ward Jr., DVM.

The anal sacs are located on either side of the anus just under the skin at the 4 o’clock and 8 o’clock positions. They connect to the anus by means of small canals called ducts. Anal sacs produce and store a dark, foul-smelling fluid. These are the same types of organs that a skunk has to scare away its enemies and mark territory. Although cats use their anal sacs for the same purpose, most domestic cats have no need to mark territory or repel predators. Because the sacs are rarely emptied, the fluid builds up, solidifies, and becomes an ideal environment for bacteria to thrive.

What diseases occur in the anal sacs?

There are three diseases that occur in the anal sacs.

1. When the fluid becomes thick and solidified, the condition is called impaction.

When bacteria grow in this material producing yellow or bloody pus, the condition is called infection.

When the infection builds to create a hot, tender swelling in the gland, the condition is called an abscess. When the abscessed material overflows the sac or the duct leading to the sac becomes obstructed, the skin over the sac breaks open, and the pus drains onto the skin.

What are the clinical signs?

Symptoms of anal sac disease are:

  • Scooting or dragging the anal area.

  • Excessive licking under the tail.

  • Pain, sometimes severe, near the tail or anus.

  • A swollen area on either side of the anus.

  • Bloody or sticky drainage on either side of the anus.

How are these diseases treated?

The treatment for impaction is to express the sacs and clean out the solidified material. For infection, the sacs must be expressed and antibiotics administered to kill the bacteria. If the sacs abscess, the abscess must be surgically drained and antibiotics administered.

How likely is it for anal sac disease to occur again?

It is not very common for cats to have recurrent anal sac disease. However, some overweight cats will have chronic anal sac problems. The anal sacs of obese cats do not drain well, thus these cats are predisposed to recurrent problems. If a cat has several episodes of anal sac disease, the anal sacs can be removed surgically. Because these sacs are virtually unused, there is no loss to the cat. It is the only way to permanently cure the problem.

Are there any common surgical complications?

Surgery requires general anesthesia which always carries some degree of risk, whether the patient is a cat or a person. However, modern anesthetics make this risk minimal for cats that are otherwise healthy.

Some cats will experience lack of bowel control after the surgery. They may drop fecal balls as they walk. This occurs because the nerves that control the anus are near the anal sacs and may be damaged during surgery. However, this is almost always a temporary problem that will resolve a few days to a few weeks after surgery.

Can anything else happen to anal sacs?

Some cats are born with anal canals that do not close well. These cats are constantly draining anal sac fluid and leaving a foul-smelling drop wherever they have been. This is another indication for anal sac removal. There does not appear to be any other way to stop this, and these cats do not outgrow this problem.

Copyright 2002 Ernest E. Ward Jr., DVM. . Used with permission.

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