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 can grow.


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.


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


  1. When the infection builds to create a hot, tender swelling in the sac, the condition is called an abscess. When the abscessed material builds too much for the sac to hold, 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 around 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 us 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 anaesthesia which always carries a very slight degree of risk, whether the patient is a dog or a person.  However, modern anaesthetics make this risk very minimal for dogs that are otherwise healthy.


Some dogs will experience lack of good bowel control. They may drop faecal 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


In our experience at East Port Veterinary Hospital, we find the surgery when required is a successful and rewarding procedure for the dog, with a very low complication rate.


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 resulting in the ducts constantly draining anal sac fluid.  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.


Can I express my own dogs anal glands?


The answer to this question is yes, but we would strongly recommend that we show you a safe and easy method of doing this first. It is possible to be to damage the sensitive area of the anus if too much force or improper technique is used.