Cat looks sunken in on sides – How to resolve it?

What are the flanks of a cat?

The region just in front of the hips and behind the last rib is called the flank in a cat. If your cat looks sunken in on his sides you will see a cavity develop in that spot. In this article we discuss what could be the cause if your cat looks sunken in on his sides. 

When does a cat looks sunken in on his sides?

A cat looks sunken in on his sides when he loses weight. So when he gets too skinny. We will discuss the cause of becoming too thin in the next section. Because a cat loses weight, fatty tissue is initially burned. The potbelly that many cats have will disappear and with further weight loss, the fatty tissue under your cat’s skin will also disappear. Your cat will then start to exercise less. After all, he has a lack of calories to use, so he is careful with them. He will have to use it sparingly. Because he moves less, his muscles will also become thinner. And precisely where the flanks are located, there is normally a lot of muscle tissue and fat. So if your cat looks sunken in on his sides, he has already lost quite a lot of weight.

Flanks are sunken in on a skinny cat

Why does my cat lose weight and looks sunken in on his sides

As mentioned, a cat looks sunken in on his sides because he loses weight. You had already understood that by now. But what causes your cat to lose weight? You can only lose weight if you burn more calories than you eat. In most cases, people already give their cat more food because they already noticed that their cat looks sunken in on his sides. And this apparently didn’t help you, otherwise you wouldn’t have ended up on this page. In that case there is probably a loss of calories somewhere inside or out of the body of your cat.

Consuming too few calories

Your cat does not consume enough calories when he eats poorly or when he gets too much exercise. In older cats this can be caused by dental problems, so check the teeth of your cat. And in cats of all ages it can be caused by nausea or abdominal pain. 

In case of poor nutrition, it is better to give cats up to the age of about 8 an easily digestible diet so that they experience less stomach ache and less nausea. It is also wise to offer them some food several times a day instead of once or twice a day. This way they will eat more food and therefore consume more calories.

Cats can also be stressed and therefore eat poorly. If you feel that your cat is under a lot of stress, try to remove the cause of the stress. Don’t know what the cause is? Then you can give him Zylkene. This increases the amount of serotonin in his brain in a natural way, making him feel more confident and relaxed and therefore eat better and more.

Losing too many calories

There are several options for this. A cat may simply be a hyperactive type and therefore need more nutrition compared to other cats. But it is also possible that a cat has worms in its intestines that are eating along with your cat. Or your cat either loses proteins through his intestines if he has diarrhea, or through his kidneys if he has chronic renal failure. With diabetes, your cat loses sugar through its kidneys. It is also possible that your older cat has an overactive thyroid gland. In that case, all cells in his body are excessively activated and that costs a lot of energy. And unfortunately, cancer is also often a major culprit when it comes to weight loss. Cancer grows and needs a lot of energy to do so.

Do you have an older cat that looks sunken in on his sides? Let’s say from about 8-9 years old? Then there is a chance that there is kidney failure, diabetes or an overactive thyroid gland. These diseases mainly occur in older cats and not in young ones. If you have a young cat with sides sunken in, there is a bigger chance that he suffers from worms or intestinal problems that cause him to lose proteins through his feces. Or he is just overly active playing outside.

My cat has sunken hips

When the problem in the cat that looks sunken in on his sides is not resolved soon enough his hips are starting to sunk in too. After all, the hips also consist of many muscles to move the hind legs and bear the weight of the body. When your cat loses weight, it will first have sides sunken in and after a while the hips will appear to stick out more. But later on, less muscle tissue will remain in the hips and the hips will protrude more. This is called sunken hips. 

When is a cat too thin?

In fact, in western countries, half of all cats are overweight. Our image of a “skinny” cat is therefore a bit clouded. In the photos below you can clearly see the difference between a cat that is too fat, a cat with a healthy weight and a cat that is too thin. A healthy cat does not look sunken in on his sides and has a tight abdomen. You can hardly feel any subcutaneous fat on the ribs in a cat of a healthy weight.

Skinny cat with flanks sunken in.
Skinny cat that looks sunken in on his sides
Cat with a normal weight.
Cat with a normal weight.
Overweight cat with a potbelly underneath.
Overweight cat with a potbelly underneath.

What can I give my cat to gain strength?

If you feel that your cat is consuming too few calories, you can temporarily supplement his food with high-quality, energy-rich canned food. For this you can use Hill’s urgent care canned food, for example. In addition, you continue to give him his regular food. Your cat should noticeably gain weight within a week or two. If not, there is probably a medical cause for the fact that your cat looks sunken in on his sides.

We recommend deworming cats once every 3 months. Have you not given your cat deworming for a long time and does your cat looks sunken in on his sides? Then you can at least give him a deworming treatment and see if he stops losing weight.

It is wise to weigh your cat before treatment. After all, you want to quickly see whether he will recover and be able to intervene quickly if it doesn’t work. You can weigh your cat by holding it in your arms and then standing on your own scale together. Then you go on there without him. The difference between the two weights is the weight of your cat. For now, weigh him every week and write down his weight! You can also use a baby scale to weigh your cat if that’s easier for you.

Does your cat continue to lose weight despite the treatment? Then it is wise to take your cat to your vet.

When should you go to your vet if your cat looks sunken in on sides

Do you have an older cat that looks sunken in on his sides? In that case, it is important that a blood test is performed to determine the cause why your cat looks sunken in on his sides. With this test they at least check for kidney failure, diabetes and an overactive thyroid. And of course they also examine many other blood values that can reveal what is going on in your cat.

But even a younger cat that continues to lose weight even though you have already given it deworming and extra supplementary food should be examined by a veterinarian.

Good luck with your cat that looks sunken in on his sides!

Hopefully your cat will have a normal weight soon again. Good luck for the both of you.