Black and white obese cat

Many cats start to put on weight after being neutered.

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Obesity in cats: causes and treatment

By Dr. Helen Donald BA BVetMed MBA MSc MRCVS Veterinarian

Updated on the

Obesity in cats can lead to health problems. Here's how to help your cat with their weight.

Obesity is sadly an all-too-common problem in cats and it can lead to a greater risk of many health problems.

How is obesity in cats treated?

In the wild, cats are very active as they hunt for food and tend to eat little and often. Two meals a day, or ad-lib feeding, and lots of sleeping means that many cats end up overweight or obese. Speak to a vet and they will recommend a combination of dietary changes and increasing exercise levels to help your cat to reach and maintain a healthy weight.

What causes obesity in cats?

Many cats start to put on weight after being neutered, so this is a time to be particularly careful with feeding. In addition, many pet foods are designed to be tasty to fussy cats and may encourage over-eating, particularly if you leave food down all day to allow your cat to graze when it wants. Obesity is also commonly seen in multi-cat households, if one cat is more dominant and eats a disproportionate share of the food you put down.

What is obese for a cat?

As a rule of thumb, being more than 20 to 25 per cent over a cat’s ideal bodyweight is classified as obese. For most cats, this is around 5kg or more, but some cats and certain breeds are quite large, so it is always best to ask a vet to body-condition score your cat and to advise you on what the best weight is for your cat.

Does dry food make cats fat?

Dried foods shouldn’t make your cat fat, if you follow the manufacturer’s feeding guidelines. Having said that, it’s often hard to measure dry foods with precision unless you have digital scales at home. Regular ‘overdosing’ by as little as 10 per cent can soon make your cat fat, so it is a good idea to ask a vet or a friend to mark a container with your cat’s daily allowance, so that you can feed accurately at home.

Does canned cat food make cats fat?

Canned foods contain a lot of water and so, weight for weight, are lower calorie than equivalent dried foods. Some canned foods are also lower in carbohydrates than dry foods and this may be helpful in maintaining a healthy weight. There is no evidence that canned foods are more likely to make your cat fat than any other food.

How can I get my obese cat to lose weight?

Cats should never be put on a crash diet, as losing weight too fast can lead to a serious condition called hepatic lipidosis. In addition, simply cutting your cat’s regular food may lead to nutritional deficiencies. Using a commercial weight-loss diet is likely to be a more healthy and manageable way to get your cat to lose weight.  

You should also try to increase your cat’s activity levels, particularly if you have cat that rarely goes outdoors. If you feed dry food, you could throw pieces to encourage your cat to run; or hide small portions around your house; or use a wobble-base dispenser, which will also slow down the rate at which your cat eats. You could also play more games with your cat. Even the laziest cat will usually enjoy short bursts of activity chasing the light from a laser pointer.  

What should I feed my overweight cat?

If your cat needs to lose weight, it’s best to ask a vet to recommend an appropriate weight-loss diet and to prepare a diet plan for you. There are plenty of good quality commercial diets, available in both dry and wet preparations, which are nutritionally balanced and designed to keep your cat feeling full for longer. If you prepare food for your cat or feed a raw diet, ask a vet to work out an appropriate feeding plan for you.

When should I see a vet?

Always see a vet before putting your cat on a weight-loss programme. The vet will weigh and body-condition score your cat and check for any underlying health issues that may be contributing to weight gain. Take your cat to a vet immediately, if your dieting cat suddenly loses their appetite or starts to vomit.

What should I ask a vet about my overweight cat?

Vets see a lot of overweight cats and are delighted when an owner recognises the problem and is ready to put their cat on a weight-loss diet. Vet nurses are also very experienced at helping clients and many practices run weight-loss clinics for free or at only minimal cost to clients. Your pet will be weighed regularly and you can benefit from lots of advice from veterinary staff and other owners.

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