What Is a Cat's Primordial Pouch?

If you've noticed your cat's belly sagging more than usual, you're not alone. Your first thought may be that your cat gained a little weight, but a cat's hanging belly can also be indicative of other heath-related issues.

Rest assured, all cats have an abdominal flap, called a primordial pouch, that swings from side to side when they walk around. But what is a cat's primordial pouch, and why do they have it?

What Is a Cat's Primordial Pouch?

Believe it or not, the primordial pouch is an important part of your cat's biological composition. As its name indicates, the pouch exists in a cat's earliest stage of development and is a fundamental part of their bodily structure. Cats are born with this sagging belly, and all cats, both male and female, have primordial pouches. Some pouches are more prominent than others. Even non-domestic big cats have them!

The pouch is an abdominal flap along their belly made up of extra loose skin and some fatty tissue. It's similar to the excess skin that cats have on their necks — called the "scruff" — which is where mama cats pick up their kittens with their teeth.

Depending on your cat's breed, size and genetic makeup, this belly flap may be prominent or discreet. The pouch on the sleek Sphynx is more evident than on a Maine Coon, for example, because of the lack of fur to cover it up. Some breeds are celebrated by "cat fancier" (cat breed registry) organizations for having a low-hanging belly. One of these breeds is the Pixiebob, a fun-loving domestic kitty whose prominent primordial pouch is listed as a desirable feature by The International Cat Association.

Why Do Cats Have a Primordial Pouch?

Now that you have a better understanding of a cat's primordial pouch, let's take a look at why they have them. A cat's hanging belly serves your feline friend in a few ways:

• Protection: The pouch's loose skin does more than just sway back and forth; it safeguards your cat's vital organs, including the liver. Whether it's two house cats roughhousing or two tigers tussling in the savanna, cats can and do get aggressive. Cats are kickers, as you see when your feline friend performs the bunny kick on a catnip toy (or your hands, arms and feet). When the claws and teeth come out, the primordial pouch is an extra layer of armor to avoid serious injury.
• Flexibility: Being the talented acrobats that they are, cats also benefit from the excess skin when they're escaping from predators. Cats have incredibly powerful hind legs, and the belly flap extends their bodies, allowing them to twist, wiggle and leap high into the air. This comes in handy, too, when they're jumping onto your kitchen counters.
• Food Storage: As Pennsylvania SPCA animal advocate Carol Erickson says, similar to when humans wear loose-fitting pants when they eat too much, the elasticity of a primordial pouch also allows a cat's abdomen to expand for food storage. This becomes especially helpful for wild cats because they tend to eat one large meal per day, but it comes in handy for house cats, too. Think of it as your cat's favorite pair of leggings or sweatpants.

What Causes a Cat-Hanging Belly?

For cats with primordial pouches that are more prominent, other factors may be at play. Here's what may be causing a more outstanding cat-hanging belly.

Obesity

Often, cat parents mistake the primordial pouch for a food belly. And while this is true for wild big cats who eat, say, an entire gazelle for dinner as opposed to a quarter-cup of cat kibble, the abdomen of an overweight or obese cat is fatty and does not sway as freely as the pouch.

An effective way to tell the difference between an overweight cat tummy and a primordial pouch is to assess your cat's body condition. International Cat Care explains that in an overweight or obese cat, you can't easily feel their ribs or other bony areas because of a "thick layer of fat." A primordial pouch does not have this layer of fat (even the thinnest cat has a pouch), and you can probably feel your cat's ribs and joints when touching their abdomen. Your veterinarian will do an assessment during your cat's wellness checkups and help determine whether or not your kitty is overweight.

Because cat obesity has become a global concern, it's a good idea to keep an eye on your cat's diet and energy level. To help your furry friend avoid weight gain and maintain a healthy size, serve them high-quality cat food and keep them engaged and active.

Pregnancy, Spaying and Neutering

If your lady cat wanders outside the home and isn't spayed, there's a chance that their sagging belly is indicative of pregnancy. In a pregnant cat, the distended belly presents at around week five. If you suspect a pregnancy, avoid touching your cat's belly, as it can harm the babies. Pregnancy can and should be confirmed with a trip to the vet.

If your cat is spayed or neutered, they may gain weight after the surgery, as explained by the experts at the Cummings School of Veterinary Medicine at Tufts University. These procedures do not affect the primordial pouch, but the hormonal fluctuations after these procedures can lead to overeating and, in turn, tummy weight gain. As Tufts recommends, discuss a new food plan with your vet, and if you have young pets, be mindful of a kitten's special nutritional requirements.

Aging

Another reason for the belly expansion is due to another biological effect that cats share with their humans: the loss of skin elasticity with age. The excess skin on the abdominal flap may sag more, which is why a primordial pouch is more prominent on older cats. Your cat's metabolism slows down as they age (another characteristic they have in common with pet parents), which makes it more difficult to lose weight, making it all the more important that you prevent weight gain before it happens. Talk to your veterinarian about potentially switching your cat to a cat food formulated for senior cats starting around the age of seven.

When to Call the Vet

As your cat ages, their abdomen can be a helpful indicator of health issues. If you feel lumps in the pouch, for instance, and your cat isn't pregnant, make an appointment with your vet. A female cat can develop breast cancer, which will present as lumps in her abdominal area, but not all lumps are cancerous, emphasizes Pet Health Network. Some cats develop benign fatty tumors called lipomas that are somewhat rare but do occur. You and your vet should regularly observe your cat's pouch so that if something unusual shows up, you can get it treated right away.

Ensure that you stay on top of your cat's health and wellness, and take comfort knowing that it's normal for your cat's primordial pouch to jiggle more with each passing year. When it comes to the question of what is a cat's primordial pouch, talk to your vet to learn more about the signs of any other health factors.