No need to be worried by skin between back legs
Some cats have what is known as a ‘primordial pouch’, which appears to be additional skin or a bit of a belly between their hind legs. Many owners are concerned this could be a sign of a cat being overweight. There is no need to be worried. This skin, with a layer of fat, is a natural feline feature unrelated to ideal weight.
It has two main purposes: It provides space for the cat to move without overstretching its skin. Particularly when jumping high or far when the hind legs are at full extension. It did also provide a source of food in difficult times. Similar to a camel’s hump, cats with a primordial pouch (also called an abdominal flap) use the fat stored there in the event of famine.
It is more common in female cats than males although it is unrelated to whether they are sterilised or have had kittens. The primordial pouch usually becomes apparent in short-haired cats at a relatively young age. The long hair of long-haired cats can disguise it in their youth and generally age-related sagging of skin makes it more visible later.
The presence of a primordial pouch does not indicate any weight problems, the layer of fat over a cat’s ribs is a far better indication of a healthy weight.