Primordial Pouch (Cat Belly Flap) in Cats

Last Updated on September 29, 2021 by Julia Wilson

What is the primordial pouch?

The primordial pouch is a loose flap of skin that runs along the length of the cat’s belly but is most pronounced towards the rear. It can often be seen swaying from side to side when the cat walks or trots.

Pet owners often attribute the primordial pouch to weight gain, but it is common on cats of all shapes and sizes, even slim ones.

What is the function of the primordial pouch?

We don’t know for sure, but the most obvious theories are that it serves four purposes.

1) The primordial pouch acts as a protection to the internal organs during a fight or attack. If you have ever seen cats in a fight, you may have noticed that they often kick each other with their hind legs and their sharp claws which could potentially damage these vital organs. 

2) Allows cats to stretch out when running at high speed or jumping.

3) For greater stomach expansion if a cat gorges on a large meal.

4) To provide a fat reserve in the event of leaner times. I’m not convinced about this because the primordial pouch is mostly loose skin and fur.

In the video below, you can see my own cat Monty on the deck. Monty has quite a large primordial pouch that sways when he moves.

What’s the difference between a primordial pouch and an overweight cat?

Obesity is a serious and growing health concern among domestic cats. It is our responsibility to keep a close eye on our cats to make sure they don’t gain too much weight.

  • The primordial pouch is a loose flap of skin, and you may notice it jiggles from side to side when a cat trots towards you. It is located on the underside of the belly, and if you look down on the cat, it will be difficult to see.
  • The obese cat’s belly has an overall rounder shape, that will not jiggle from side to side the way the skin of the primordial pouch does. You should be able to feel the ribs when you run your hands along the cat’s sides; if you can’t, the cat is overweight and should seek veterinary advice on ways to help the cat get down to a healthy weight.

The cat below is severely obese and runs the risk of developing several diseases due to her weight. Obesity is an overall increase in the cat’s size compared to the primordial pouch, which is confined to the underside of the belly and most prominent in front of the rear legs.

Does spaying and neutering cause the primordial pouch?

No, cats either have a primordial pouch or they don’t it has nothing to do with spaying or neutering. Entire cats, as well as spays and neuters, can all have a primordial pouch.

This is an obese cat

Primordial pouch removal

It is not possible to get rid of the primordial pouch with weight loss, and it would be unethical to surgically remove it. In no way does the primordial pouch have a detrimental effect on the cat.

Do all cats have a primordial pouch?

No, not all cats have a primordial pouch, however it is widespread in both purebred cats as well as moggies (mixed breeds).

Cat breeds permitted to have a primordial pouch

Some cat councils/associations permit the primordial pouch in certain breeds. What that means is the primordial pouch is an allowance that has been written into the breed standard for those particular breeds.

Pixie-bobANCATS breed standard (page 98)

The Pixie-Bob is an American breed that is said to be a cross between a wild bobcat and a domestic cat. In reality, it is a breed developed from a domestic cat with a naturally bobbed tail.

Egyptian MauCFA breed standard

The Egyptian Mau is the oldest domestic cat breed and is thought to have descended from the African Wild cat due to its remarkably similar appearance.

Bengal – CCCofA breed standard

The Bengal is was created by Jean Mill who crossed an Asian Leopard Cat with domestic cats to create wild-looking cats with a domestic temperament.

Other names for the primordial pouch

  • Belly flap
  • Spay sway
  • Apron
  • Fat pouch
  • Belly bag

Frequently asked questions

What age do cats develop a primordial pouch?

The primordial pouch usually begins to develop around six months of age, when the cat moves into adolescence.

Is a primordial pouch dangerous? 

No, a primordial pouch is not dangerous to cats.

Why is my cat’s primordial pouch so big?

Every cat is different, some have a barely visible primordial pouch, others have a big primordial pouch.

Why does my cat have a belly after being spayed? 

The primordial pouch develops from 6 months, which coincidentally is the same time many cats are spayed or neutered. This may explain why many people attribute spaying and neutering to the development of the primordial pouch. But this is purely coincidental.

Do male cats have a primordial pouch? 

Yes, male cats have a primordial pouch, in fact, it is common in both sexes.

What does a cat’s primordial pouch feel like?

The primordial pouch is made up of loose skin and fur and feels soft and almost jelly-like to the touch.

Why is my cat getting so fat? 

If your cat is getting fat, schedule an appointment with a veterinarian to determine the cause. Common causes of weight gain in cats include overeating, not enough exercise and pregnancy.

Why is my cat’s primordial pouch so big?

Each cat is individual and the size of a cat’s primordial pouch can range from small to large.

Is it normal for a cat to have a hanging belly?

It is completely normal for a cat to have a primordial pouch, which must be differentiated from a hanging belly due to obesity. If you have any concerns about the size or shape of your cat’s belly, speak to a veterinarian.

Does a primordial pouch go away?

No, a primordial pouch is normal part of the cat’s anatomy and does not go away.

Primordial pouch or fat

All skin has some degree of subcutaneous fat, however on cats who are a healthy weight, this is minimal. The primordial pouch feels soft and moves freely from side to side. Extra abdominal fat feels firmer and there is no sway when the cat moves.