Keeping your cat at a healthy weight

What is a healthy weight for a cat?

A difficult question to answer, as just like humans, there is a lot of variation in the size of individuals. 5kg may be perfect for a large male cat, but in a petite female, this would be overweight. Just like the BMI scheme in humans tries to address this problem, the veterinary profession along with pet food manufacturers, have come up with Body Condition Scoring (BCS) for pets. This assesses the shape of the animal, rather than its weight. As long as the shape is ideal, then it follows that the cat’s weight at that point in time must be ideal too.

Find out more about Body Condition Scoring here >

Why is obesity bad for cats?

Being overweight is not only uncomfortable for the cat, but it will lead to increased risk of the development, or the progression, of the following diseases:

  • Diabetes mellitus
  • Lower urinary tract infections, such as cystitis
  • Osteoarthritis caused by stress on the joints
  • Non allergic skin disease, because overweight cats cannot groom themselves properly
  • Hepatic lipidosis – a disease where fatty deposits accumulate in the liver.

Obesity also causes other complications:

  • An increased risk to a general anaesthetic
  • Decreased immune function, which in turn can lead to other serious conditions
  • Breathing and heart problems.

What causes cats to be overweight?

Weight gain happens when cats eat more calories than they are using up. The excess energy is stored then stored as fat. Cats are naturally predators and as such are carnivores. This means they eat meat and in their natural habitat, their diet would consist of small prey mammals, birds and sometimes fish. This diet is naturally high in protein and low in fat with very little carbohydrate.

This diet helps to keep to keep them fit and muscular – which of course is important if you have to catch your own dinner!

Nowadays, our feline friends are fed diets which are very tasty and energy dense. This means they often eat a lot more than they need. Once a cat is over 2 years old, many tend to lead quite sedentary lives and sleep a great deal - not great for burning off the calories!

Owners can sometimes be reluctant to allow their cats out at night. Therefore, not only do they do less hunting, but they don't even need to use any energy up to keep warm. Despite this, cats do not develop obesity as easily as dogs or people, so it seems some individuals are just more at risk than others. If yours is one of those, don't despair. There are lots of things you can do to help. Ask your veterinary team who will be full of helpful advice.

What causes cats to be underweight?

Of course there are also instances where a cat may be underweight. As we said earlier, cats in the wild that have free access to a hunting ground, will feed on a natural diet and maintain their body weight quite happily as long as they are healthy. If a cat is denied access to hunting or other food source, of course they will lose weight. This can happen if your cat goes missing or gets stuck somewhere for any length of time. Fortunately cases like this are rare. The overwhelming reason for cats losing weight and becoming too thin, is disease and illness. If you are worried that your cat is losing weight without trying, then you should see your vet as soon as possible.