Anal Glands

dog

Make a circle with your left thumb and forefinger. Take your right thumb and forefinger and place the tips on either side of the circle you made—at about the four o’clock and eight o’clock position. Now have someone lift up your dog or cat’s tail and put your circle over the anus. The anal glands (or more precisely, anal sacs) are approximately where your right thumb and fore-finger point.

So now that you know where to find them on your dog or cat, what the heck are they? The anal sacs are sebaceous glands which secrete fluid that is generally thick and dark colored and smells fishy. Many wild animals can release the contents of the sac voluntarily, producing a very malodorous liquid used for scent marking or in self-defense, particularly in the case of a skunk.

Opossums use their anal glands to “play possum.” Their glands secrete a liquid that smells like a rotting carcass, making the predator think the animal has been dead a long time and, thus, avoiding it. Hyenas produce a gooey fluid from their anal glands wonderfully named hyena butter. This fluid is used to mark their territory. Dogs and cats aren’t usually able to voluntarily release the contents of their sacs, but if they get scared, the anal sacs often empty on their own.

Interestingly, humans also have anal sacs, although they are classified as eccrine-secreting sweat glands. They are located in the wall of the anal canal and secrete fluid into ducts which open into the anal crypts. These are located approximately one-half inch inside the rectum. Thank heavens these sacs appear to have little function in humans, although if you are really scared, they may release some fluid. If they become obstructed, however, it can lead to a perianal infection.

In dogs and cats, defecation and walking helps push out the contents of the sacs, but some animals are unable to empty the sacs on their own. When this occurs, the sacs become impacted (full) and uncomfortable. Dogs will often scoot their butt on the ground in an attempt to empty the glands. Other dogs will lick excessively at their anus or keep turning and biting at their tail region. I had one dog that would vomit when his anal glands were full, but had no other clinical signs.

Some dogs just act off—shivering, not wanting to walk, holding their tails down, or hiding. Cats may lick the fur off under their tails or defecate outside the litter box. Impacted anal sacs are painful, making defecation uncomfortable, and can lead to constipation. Sometimes the overly full glands will leak when the pet is resting, often on your lap.

If your dog scoots once or twice and then seems fine for a period of time, he likely expressed his anal glands himself. Adding a higher fiber supplement or switching to a high-fiber food helps bulk up the stool, which may be more effective at emptying the sac as it passes by. But if the scooting or licking continues, then the glands need to be expressed. While groomers and some pet owners express anal glands externally, it may not be sufficient to release all the material. If you want to learn how to express anal glands on your dog—I definitely don’t recommend trying it on your cat—ask your friendly veterinarian or veterinary technician to give you a tutorial. Be forewarned, and I speak from experience, anal gland material that doesn’t go directly into a tissue or your gloved hand can end up on your clothes, in your hair, or on the wall and will smell pungent for quite some time.

If you aren’t up to expressing the glands on your own, your veterinarian or veterinary technician will do it internally, which is better for completely emptying the sac. Internal expression also gives the vet a chance to evaluate the contents to see if there is blood or pus, and to feel for any thickening or mass in the sac itself. If there’s an infection, then the vet can prescribe antibiotics and might instill antibiotics directly into the gland to help clear things up.

If your pet is scooting or licking frequently and you don’t have the glands emptied, the impacted glands can develop an infection or abscess due to contamination with fecal matter. If this occurs, there will be a painful swelling to the side of the anus, and the infection can drain through the skin, causing a bloody discharge. If this happens to your pet, you may notice blood when they defecate or sit down and a bad odor from the back end. Anal gland abscesses require a veterinary visit and antibiotics. The vet will likely try to express the other side in case it is also impacted. Again, abscessed anal glands are painful, and sometimes sedation of the pet is required to clean up the area.

Recurrent anal gland issues can be due to conformation—the gland is not situated to make normal drainage with defecation possible. Smaller-breed dogs tend to have more anal gland issues, although this might be because of groomers often expressing the anal glands, causing them to not function well on their own; obesity; or allergies, which can cause inflammation of the gland.

If your pet has recurrent anal gland issues requiring frequent emptying by the vet or antibiotics for infection, you can have the anal glands surgically removed. It’s best to have an experienced veterinary surgeon do this procedure as there are many nerves in the area that control the anal sphincter. If they are damaged, your pet may become fecally incontinent, which certainly isn’t ideal.

So when you see your dog or cat scooting or paying extra attention to their rear end, think about anal glands and make an appointment to see your veterinarian. Anal gland expression is a procedure that is done on an almost daily basis in the vet clinic and is rather rewarding for all involved!

Photograph by Brenda Eckhardt

Lori Scarlett, DVM, is the owner and veterinarian at Four Lakes Veterinary Clinic. For more information, visit fourlakesvet.com .