Primordial Pouch in Cats: Our Veterinarian Explains

What is the primordial pouch (Cat Belly Flap)?

The primordial pouch (Cat Belly Flap) 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 they may serve the following three purposes.

1) The primordial pouch acts as 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. 

Cats fighting
Image rihaij, Pixabay

2) The pouch may allow cats to stretch out when running at high speed or jumping.

Cat stretched out when running
Image rihaij, Pixabay

3) The pouch may be used for greater stomach expansion if a cat gorges on a large meal.


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.

  • Cats with primordial pouch: The primordial pouch is a loose flap of skin, and you may notice it jiggles from side to side when a cat trots toward you. It is located on the underside of the belly, and if you look down on the cat, it will be difficult to see.
    primordial pouch on white cat

  • Obese cats: The obese cat’s belly has an overall rounded 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 (The primordial pouch is confined to the underside of the belly and most prominent in front of the rear legs).

    Obese cat
    Obese cat with overall rounded shape

Do lions and tigers also have a primordial pouch?

Yes, large cats such as lions, cougars, leopards, and tigers all have primordial pouches.

Primordial pouch on big cats

Does spaying and neutering cause the primordial pouch?

No, cats either have a primordial pouch or they don’t and it has nothing to do with spaying or neutering. 

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?

Not all cats have a primordial pouch
Image Nynke van Holten, Shutterstock

No, not all cats have a primordial pouch, however, it is widespread in both purebred cats as well as 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 that the primordial pouch is an allowance that has been written into the breed standard for those particular breeds.

Pixie-bobANCATS breed standard (page 98)

Primordial pouch on a Pixiebob
Image COULANGES, Shutterstock

The Pixie-Bob is an American breed that is widely rumored 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 and no bobcat DNA has ever been detected in the breed.

Egyptian MauCFA breed standard

Egyptian Mau
Image COULANGES, Shutterstock

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

Bengal cat
Image Seregraff, Shutterstock

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

Does my cat’s primordial pouch mean my cat is too fat? Do I need to do anything?

Just because your cat has a primordial pouch does not mean they are overweight. However, many overweight cats store excess fat in their pouches. When petting your cat you should be able to easily feel the spine and ribs.

When looking at them, you should see a small tuck in their abdomen right before the hips. If your cat is round and you can not easily feel the spine and ribs when you gently stroke them, they are most likely overweight. You should make an appointment with their veterinarian to assess their weight and get help with appropriate weight loss.

Why is it called a primordial pouch?

Primordial means that the object in question has been present “since the beginning.” With cat primordial pouches it is likely that they were named this referring to the fact that cats have had these pouches since they began as a species.

Does the primordial pouch allow my cat to run faster?

No one knows for sure what the exact purpose of the primordial pouch is, but theories do suggest that they may allow for extra stretching of that cat’s body when they run and jump.

Do humans have a primordial pouch?

Primordial pouches are not recognized features in human anatomy.

Other Frequently asked questions

At 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. Though no one knows the exact purpose of the pouch, all of the current theories are helpful to cats. On the other hand, being overweight is definitely dangerous to your cat and may lead to many different diseases such as diabetes, heart disease, and arthritis.

Why is my cat’s primordial pouch so big?

Every cat is different, some have a barely visible primordial pouch, and others have a big primordial pouch. However, you may need to check with your veterinarian to ensure that your cat is not overweight.

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.

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 a normal part of the cat’s anatomy and does not go away. The pouch will usually start to be visible as the cat reaches maturity, between 6 and 9 months. The pouch may become more noticeable as the cat ages or if they gain weight.

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. 


  • Dr Whittenburg, Hospital Director

    Dr. Jamie Whittenburg (DVM) is the director of Kingsgate Animal Hospital, a full service veterinary hospital in Lubbock, TX, and a medical director at Cat World. She graduated from Kansas State University College of Veterinary Medicine in 2006. Dr. Whittenburg then went on to pursue post-graduate training at Texas A&M University. She worked as an associate veterinarian in Fort Worth before the Hub City called her home. In Lubbock, Dr. Whittenburg continued her work as an associate veterinarian and in academia. On May 1st, 2013, she opened her own hospital, Kingsgate Animal Hospital, in her hometown of Lubbock, TX. She has a special interest in feline medicine and surgery.

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  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio

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