Anal Gland "Expression" in Cats

Anal Glands: One of Your Cat's Best Tools for Communication

Cat walking on fence
Image by Chris Winsor / Getty Images

Anal glands are not usually a common topic of discussion among cat aficionados and are rarely something we even think about until something goes wrong with them. My own quick, but unforgettable lesson on anal glands came one day, when my son pointed out a horrible "odor of infection" around Jaspurr's hind quarters.

Being quite familiar with the odor which abscesses extrude from previous experiences with other cats, we agreed that it did smell like Jaspurr had an infection of some sort.

Although there was no obvious tenderness in any of his nether parts, we whisked him off to our veterinarian for a checkup.


Dr. Dietrich asked a number of questions, and when he asked about "scooting around on the floor," I could sense where he was heading. Sure enough, when the vet tech brought me a sampling of the substance they had "expressed" from Jaspurr's anal glands, it was exactly what I had smelled earlier. We were sent home with a receipt and a somewhat grumpy and embarrassed cat.

What are anal glands and what do they do?

Technically, what we see and describe as "glands" are actually anal sacs, which contain the glands that secrete an oily, strong-smelling substance. Both male and female cats have anal glands, as do dogs and some other animals. You can see the anal sacs beneath the anus at roughly the 5 o'clock and 7 o'clock position in the attached photo. The photo shows the approximate positions of the anal sacs.

They are described as "pea-sized" in small dogs, and are smaller in cats.

In the wild, cats "express" this substance along with their feces, for marking purposes, a practice akin to leaving a calling card for subsequent visitors to read. As the anal canal opens for the feces to pass, the hard contents press against the anal glands, causing secretion of some of the substance.

Cats will also spontaneously express their anal glands when alarmed, much as skunks do.

Some veterinarians believe the anal gland is vestigial because it requires hard feces to properly express its fluid. They argue that the commercial cat food we give our kitties produces softer "poop," which doesn't exert the necessary pressure to make the gland work right. On the other hand, cats still "express" their anal glands when alarmed or upset (which was evidently the case with ​Jaspurr), and it would certainly serve as a territorial marking, judging from the strong odor. Commonly-cited spontaneous expressions occur when a rectal thermometer is used on a cat, or when a groomer is working near the rectal area.

Some cats need to have their anal glands manually expressed from time-to-time, usually by a veterinarian or groomer, although a cat owner can learn the procedure, which is fairly straightforward.

Other Potential Problems with Anal Glands

  • Impaction: If a cat fails to express his or her anal gland regularly, the material within can build up and turn into a waxy hard impacted piece of "sludge." Scooting across the floor or licking the anal region can be signs of anal gland impaction. Impaction is not as easily treated as simply expressing the gland, but usually involves cleaning out the impaction under sedation and administering oral and/or topical antibiotics, along with pain killers.
  • Anal Gland Infection: Infection often accompanies impaction, or may be present by itself. Infected anal glands can rupture to the surface much like any other abscess. In this case, veterinary treatment is essentially the same, usually by lancing, debriding, flushing with an antiseptic solution, and administering antibiotics.
  • Cancer: Chronic and advanced anal gland problems such as recurring abscesses can eventually lead to cancer. Surgical removal of the anal glands is sometimes offered in chronic cases, to prevent the possibility of cancer. It is serious surgery, but there are no known drawbacks to the cat who has had his or her anal glands removed.

How can I help prevent these problems?

Heightened awareness of your cat's usual physical condition and routines is as critical with his anal sac as with other body functions.

Some experts believe a diet high in fat can contribute to thick, viscous anal sac secretions, which can harden and cause impaction. Others hypothesize that a diet higher in fiber will create firmer stools, thus facilitating the expression of anal sac substance. Your experience will vary, but diet is something you can discuss with your veterinarian. If you are interested in diet modification, the A-Z Food Comparison section offers both fat and fiber percentages (and other nutritional values) of many high-quality cat foods, along with major brands.

If your cat has had anal sac impaction in the past, or regularly needs to be manually expressed, you probably already are paying close attention to potential symptoms of problems.

If your cat has had no previous problems, just remain aware and be observant of changes. Being aware of your cat's normal body condition is probably the best thing you can do for your cat's overall health, in the long run.