ANAL SAC DISEASE
What are anal sacs?
The anal sacs are located on either side of the anus at the 8 o'clock and 4
o'clock positions; they are positioned just under the skin. They connect to
the anus by means of small canals or ducts. Anal sacs produce and store a dark,
foul-smelling fluid. These are the same type of organs that a skunk has to scare
away its enemies. Although dogs can use these for the same purpose, most dogs
live in an environment that has no enemies. Because the sacs are rarely emptied,
the fluid builds up, solidifies, and becomes an ideal environment in which bacteria
What disorders can occur in the anal sacs?
There are 3 diseases that occur in the anal sacs.
1. When the fluid becomes thick and solidified, the condition is called impaction.
2. When bacteria grow in this material producing a yellow or bloody pus, the
condition is called infection.
3. When the infection builds to create a hot, tender swelling in the sac, the
condition is called an abscess. When the abscessed material overflows the sac,
the skin over the sac breaks open, and the pus drains onto the skin.
How will I know if my dog is having problems with its anal sacs?
Symptoms of anal sac disease are:
1. Scooting or dragging the anal area.
2. Excessive licking under the tail.
3. Pain, sometimes severe, near the tail or anus.
4. A swollen area on either side of the anus.
5. Bloody or sticky drainage on either side of the anus.
How are the various anal sac diseases treated?
The treatment for impaction is to express (squeeze out) 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 abscessate, this will need surgical
draining by your veterinary surgeon and antibiotics administered.
My dog has had several bouts of anal sac disease. Is there a long-term cure?
Many dogs have recurrent anal sac disease. Some breeds of dogs, such as Poodles,
commonly have problems. The anal sacs of obese dogs do not drain well, and thus
these dogs are predisposed to recurrent problems. If a dog 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 dog. It is the only way to
permanently cure the problem.
Are there any complications of the surgery?
Surgery requires general anesthesia which always carries some degree of risk,
whether the patient is a dog or a person. However, modern anesthetics make this
risk very minimal for dogs that are otherwise healthy.
Some dogs will experience lack of good bowel control. They may drop fecal balls
as they walk. This occurs because the nerves that control the anus are very
near the anal sacs and may be damaged during surgery. However, this is almost
always a temporary problem that will usually resolve in a few weeks
My dog frequently leaves a foul-smelling drop of liquid on the furniture.
Is this related?
Some dogs are born with anal canals that do not close well. The ducts constantly
draining anal sac fluid and these dogs leave a foul-smelling drop where they
have been. There does not appear to be any way to stop this, and these dogs
do not outgrow this problem. This is another reason for anal sac removal.
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