When I think of anal gland problems, I usually think of dogs, and there’s a good reason for this: Dogs are far more likely to have blockages and other issues with those little sacs than cats are. But, as I learned last week, cat anal glands can suffer blockages, too.

When I brought Siouxsie in for her three-month post-radioactive iodine therapy checkup, my vet noticed something odd: One of her little sacs was swollen to the size of a marble. Needless to say, we got that taken care of right away. “Better them than me,” I said as one of the techs brought Siouxsie back to the treatment room.

So, just what are cat anal glands and what do they do? Here are some things to know about cat anal glands:

The 9 Facts About Cat Anal Glands

1. They’re not actually glands, they’re sacs

The anal sacs are lined with glands that produce an oily and stinky substance. If you look at your cat’s butt, you may be able to see the outlets of the anal sacs at about four and eight o’clock in relation to the anus.

2. In the wild, secretions from cat anal glands are used to mark territory

When a wild cat poops, the passage of feces through the anal canal squeezes the anal glands and expresses a little bit of that strong-smelling fluid. This serves as an extra tool for marking the boundaries of that cat’s range. Domestic cat anal sacs are considered vestigial, although they do seem to play a large role in cat social dynamics.

3. That butt sniffing thing? It’s all about the anal sacs

The secretions from cat anal glands are part of the unique smell that identifies individual cats. This is why cats often greet one another with mutual butt sniffs.

4. Cat anal glands can get impacted

If the oily substance plugs the opening of the anal sacs, the secretions build up inside and can cause pain and discomfort. Cat anal sacs are probably about the size of pine nuts, but they can grow to several times that size when the openings are clogged.

5. Cats don’t show symptoms for impacted anal glands like dogs do

When dogs get impacted anal glands, they tend to scoot their butts along the floor and lick the area excessively. Cats, with their legendary ability to hide their pain, just bear the discomfort. If you don’t see a problem, this can result in serious issues.

6. Some cats may be more at risk for anal gland issues than others

“We are not sure why some cats develop problems with their anal glands,” says Jessica Stern, DVM, DABVP (feline), of Cats Exclusive Veterinary Center in Shoreline, Washington. “In some cats, it is due to narrowing or strictures of the anal gland ducts (the tube between the anal gland and the rectal wall). The narrowing may be congenital or acquired. Obese cats can also have problems with completely emptying their anal glands. In other cases, we don’t know why it happens.” Dr. Stern adds that underlying food or environmental allergies can cause issues with cat anal glands.

There is no way to fully prevent cat anal gland issues, but keeping cats at a healthy weight can help. Some vets say that anal sac impactions are more common in overweight and inactive cats, perhaps because obese kitties can’t clean their bottoms as well as their leaner kin, and a lack of exercise could lead to constipation. Constipated cats don’t have frequent-enough bowel movements, and this may cause the secretions to plug the gland openings.

In some cases, Dr. Stern says, increasing fiber in the diet can increase the volume of the feces, which may help express the glands during defecation. Addressing underlying allergies can also help.

7. Treatment of cat anal sac issues

A supplement called Glandex can help cats with chronic anal gland problems. Dr. Stern says that although she hasn’t tried Glandex with her patients, “the ingredients make sense — pumpkin fiber to increase fecal bulk, antioxidants to help with inflammation, and probiotics to maintain healthy GI bacteria.”

“My typical recommendation is to increase fiber in the diet — this may or may not actually help, and you do not want to add too much fiber (then constipation may be a problem), but it is something to try,” Dr. Stern says. “We usually only recommend surgical removal of the glands if the problem is chronic or recurrent.”

8. Cat anal glands can rupture

“If the anal gland ruptures due to an abscess, then the area is typically cleaned and the cat is started on antibiotics, pain medication and possibly anti-inflammatory medication to treat the infection,” Dr. Stern says. “A surgery to open up and drain an unruptured abscess may need to be performed.” However, she adds, anal sacculectomies (the surgery to remove the anal glands) are not considered urgent or immediate surgery. “It is usually recommended to have this surgery after the abscess, infection and inflammation has resolved,” she advises.

Even after a rupture, cats can have another anal gland impaction or abscess in the same anal gland, or it can happen on the other side, so the anal gland issue can still be a problem.

9. Surgery may be performed on cat anal glands — in some circumstances

When it comes to anal gland surgery, “we typically send a cat to a board-certified surgeon,” Dr. Stern says. The price of the surgery can vary tremendously depending on where you live, but Dr. Stern estimates that in the greater Seattle area, you can expect to pay somewhere between $1,500 and $2,000.

“The real risk would be damaging nerves in the area and causing [temporary or permanent] fecal incontinence,” says Dr. Stern. “The benefit would be removing the potential for subsequent impactions or abscesses.” As long as there are no complications, the removal of cat anal glands doesn’t cause any long-term problems. “The glands are really just scent glands and don’t serve any other purpose than olfactory communication,” Dr. Stern says.

Thumbnail: Photography © ablokhin | iStock / Getty Images Plus.

Learn more about related health issues with Catster.com:

• 3 Questions You Had About Cat Butts — Answered
• Handling Your Cat’s Poop Problems: From Diarrhea to Constipation
• Cat Poop — When to Worry (or Not!) for Cats of All Ages