Anal Glands in Cats: What Are They, and How Do They Work?

The anal glands (also called anal sacs) are a set of scent glands that empty into the rectum in many mammals, including cats. When they work properly, you might never know these glands are there.

However, some cats can have irritation and dysfunction of these glands, which can be very frustrating to treat and manage.

What Are Anal Glands in Cats?

Anal glands are small, pea-sized sacs found on either side of the rectum in cats.

These sacs have cells that release a strong-smelling fluid into them. Two small ducts release this fluid onto the stool when a cat defecates.

The smell of the fluid is used by cats to mark territory.

Cats may also release their anal glands when they are surprised or frightened. Both male and female cats have anal glands.

Anal glands are completely inside the body. They are normally not visible in cats, other than sometimes the small, 1 mm openings in the rectum (usually in the 4 o’clock and 8 o’clock positions in the anal opening).

How Do Cat Anal Glands Work?

When they work correctly, these glands fill slowly with a thick fluid.

The pressure of the rectal muscles during defecation (or during a fear response) squeezes this fluid through the narrow ducts and onto the stool, or into the environment.

Why Do Cats Need Anal Glands?

Cat communication is a complex interaction of sounds, smells, and body language that humans are just beginning to understand.

Scent marking and scent glands contribute significantly to how cats interact with each other (and possibly humans in their families). 

While there are limited studies on how anal gland scents are involved in communication, cats’ emotional health is highly linked to their ability to communicate properly.

Though cats with abnormal glands can have them removed and live normal lives, working with your vet to avoid surgical removal of the glands is most recommended.

Do Cats Need Their Anal Glands Expressed?

Healthy cats without anal gland abnormalities should not need their anal glands manually squeezed or expressed.

However, for a variety of reasons, gland material may become thickened or infected and a cat may need anal gland expression to make them more comfortable.

Cat gland expression should be done by—or at least done under the supervision of—a veterinary professional. The glands are very small, and restraining cats safely for this procedure can be difficult.

Anal gland expression is rarely done when cats are not showing clinical signs of discomfort.

Signs of Anal Gland Issues in Cats

Signs of anal gland disease or dysfunction can be very difficult to note at home, because cats like to hide symptoms of illness and discomfort.

Symptoms that may call for having your cat’s anal glands checked by your vet include:

• Scooting or dragging their hind end on the ground

• Vocalizing during defecation

• Defecating outside of the litterbox

• Blood or discharge noted under the tail

• Blood in the stool

• Obsessive grooming under the tail

• Red/irritated rectum

• Fishy, foul-smelling liquid on furniture or bedding

Physically, these symptoms are seen when the gland is impacted (when thickening of the material in the gland or an abnormality in the duct makes normal expression difficult) or infected (when bacteria moves into the gland and causes swelling).

Anal glands that are very impacted or infected may rupture in time, creating a visible wound under the tail.

Ruptured glands usually need flushing and antibiotics.

Causes of Anal Gland Issues in Cats

Expression, flushing, and sometimes antibiotics can help a cat with anal gland issues feel better quickly.

Most anal gland issues in cats are due to systemic problems that will need to be fixed to keep the glands working normally.

Common causes of anal gland issues include:

• Allergies

• Low fiber or poor-quality diet

• Obesity

• Diarrhea or inflammatory bowel disease

• Cancer or tumors of the anal gland or rectum

The cause of the gland issue may not be easy to figure out, so it’s important to work closely with your veterinarian to come up with a good preventative strategy.

Prevention of Anal Gland Issues in Cats

Feeding a high-quality diet, giving good parasite prevention, and keeping your cat from becoming obese are the best ways to prevent anal gland issues.

Some cats may develop issues despite your efforts because of underlying illness and genetics.

Watch for issues like constipation or diarrhea, and work with your veterinarian to treat these conditions right away to avoid complications with the glands.

Do not express your cat’s anal glands unless they are truly symptomatic for anal gland issues, and it has been recommended by your veterinarian.

Repeated expression of the gland when it isn’t needed can lead to formation of scar tissue and complications.

If medical management of your cat’s anal gland issues is unsuccessful, your veterinarian may recommend surgical removal of the glands.

Anal gland surgery is very complex and should only be considered in cases where tumors are suspected or when all other avenues of medical treatment have failed.