Anal Sac Disease in Cats & Dogs

By April 20, 2021 No Comments

What are anal sacs?

The anal sacs are located on either side of the anus at the 9o’ clock and the 3o’ 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 and cats can use these for the same purpose, most 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.

There are three diseases that can occur:

  1. Impaction- where the fluid becomes thick and solidifies.
  2. Infection- where bacteria grows in this material producing a yellow or bloody pus.
  3. Abscess- where the infection builds to create a hot, tender, and swelling in the gland. When the abscessed material overflows the sac, the skin over the sac breaks, opening and allows the pus to drain onto the skin.


Symptoms of anal sac diseases 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, pus or sticky fluid draining from either side of the anus


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 have abscessed, the abscess must be surgically drained and antibiotics administered.