Why is my cat losing weight? 6 Reasons

And what could it mean for your cat’s health and wellbeing?

Every cat owner wants their cat to be healthy and happy, which why it’s so concerning to us as pet parents to see our cat losing weight and not know why. They may be independent creatures who don’t need our help catching birds or entertaining themselves, but they do need somebody looking out for them when it comes to their health.

As a pet parent, it’s your job to notice the signs and symptoms of any underlying health problems: one of which is weight loss. Weight loss can often be indicative of a health problem, and here’s why you need to take rapid or unexpected weight loss seriously when you notice it in your cat.

Signs of a cat losing weight

Cats are naturally slender so it’s easy to overlook weight loss in the beginning stages. It’s important that you check your cat on a weekly basis – whether that be through grooming or a good old couch cuddle sesh. This way, you know how their body looks and feels when they are at a normal weight. If you regularly assess your cat’s health, it will be easy for you to pick up any changes.

When you look at your cat from a birds-eye view, it’s normal to see a tuck at the waist. The tuck should be noticeable but not extreme. Apart from looking at your cat, you’ll need to feel alongside their body. At a healthy weight, you will be able to feel your cat’s ribs underneath a layer of fat. If you can feel its ribs protruding or if they are visible, your cat is most likely underweight.

Discover: 5 major signs your cat is sick (& how to afford vet visits)

Health complications that lead to a cat losing weight

If you notice your cat has lost weight, the first call of action is to get them to the vet. It could just be that your cat is not eating enough and if that is the case, you can solve it at home. But there could be another, more complicated reason your cat is on the skinny side.

Chronic kidney disease

Weight loss is a symptom of kidney dysfunction, which is common for senior cats. The kidneys are responsible for removing waste from the blood, hormone production and the production of red blood cells. You should also look out for other symptoms like excessive thirst and urination, fatigue and loss of appetite.


Diabetes mellitus is also common in cats and affects their body the same way diabetes affects humans. Diabetes affects how the pancreas produces insulin, which has a negative effect on the glucose in your cat’s bloodstream. Diabetes is easily treatable if you get to the vet on time. Some cats are even able to go back to normal health with the right diet and medication.


Cancer can target any part of the body. Common cancer in cats is Lymphoma and is often found in the gastrointestinal tract. The general effects of cancer are obvious weight loss, muscle waste and pain. Treating your cat’s cancer is expensive.


Just because cats have the attitude to end all attitudes, it doesn’t mean they aren’t susceptible to stress. Especially if there has been an environmental change. Cats don’t often make their stress obvious to you which can result in health complications later on.

Stress often leads to a loss of appetite or eating which in turn, leads to weight loss. Your vet can advise you on how to approach your cat’s anxiety whether that be through medication or changes to their environment.

Read this: Why Do Cats Hide from Their Owners? Plus 6 Common Hiding Places

Dental problems

If your cat’s mouth hurts, it’s clear why they wouldn’t want to eat. Other dental symptoms to look out for include pawing at the mouth, bad breath or bleeding. If you notice any of these signs you’ll want to get your cat to the vet ASAP as dental issues can cause extreme pain and lead to nasty infections.

Gastrointestinal Problems

GI issues are any issues that affect the stomach and digestive system. There are plenty of diseases and illnesses that target the GI tract and can cause your cat to lose a lot of weight. This could be due to food not being digested properly or your pet is unable to eat. Other symptoms to look out for include vomiting, diarrhoea and fatigue.

What to do if my cat is losing weight

Even if you feel like an ecat losing wrightxpert, you should never take an animal’s health into your own hands. Book an appointment with your vet to get a proper diagnosis and take it from there! And don’t forget to make sure you have pet insurance to help out with those vet bills (Oneplan Pet Insurance is a great option if you’re looking for comprehensive cover that’s also affordable).

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