Obesity is the number one nutritional disease in cats. Approximately 40% of cats are medically obese. Obesity is defined as being 20 percent or more over the ideal body weight. The best way to tell if your cat is obese is by feeling the ribs. You should be able to touch the sides of your cat and feel each individual rib. Not to the point that the rib is jutting out, but to the point that you can feel the ribs underneath the skin and a small layer of fat. You should also be able to follow each rib up to the spine. If you can’t feel your cat’s ribs or follow them up to the spine, your cat is overweight.

Being overweight can cause a pet to be at risk for medical problems such as diabetes, cardiovascular disease, respiratory disease, liver disease, greater surgical/anaesthetic risk, and musculoskeletal/joint dysfunction. Cats eat a certain number of calories per day. They also exercise (play etc.) to burn a certain number of calories per day. If they take in more calories than they expend they will gain weight. As it is difficult to put your cat on a diet (especially if you have multiple cats in the same household) it is always easier to not let your pet get obese in the first place.

Cats who are obese are usually overweight for one or more of the following four reasons:

  • Overeating or improper eating
  • Lack of exercise
  • Genetic predisposition
  • Hormone imbalances

If you think that your cat has a hormonal condition, such as hypothyroidism, which is causing the weight problem you should take your cat to the vet for a diagnosis.

Symptoms to look for:

  • Unable to feel ribs to the touch
  • Fat deposits over back, tail, thorax and spine
  • Absence of discernable waist
  • No abdomen tuck
  • Abdominal distention


If your cat is overweight for a hormonal or medical reason your veterinarian will propose treatment to deal with the disease first, which should help the weight problem.

If your cat is obese due to simply overeating or underexercising then it is time for a diet! Please note that you should consult your vet before beginning any diet program for your pet. Here are some types of diets that your pet might be put on: 1) Put your cat on a low-calorie high-volume food. This will help fill your cat’s stomach while giving him/her less calories. 2) Start giving your pet smaller portions as well. This may be more difficult if you have multiple cats or if your cats are allowed to eat using a self-feeding method. 3) Try to cut back on treats and table food. If you do still want to give occasional treats you may want to have your vet recommend some lower calorie ones. Just as people still like an occasional treat while on a diet, so do cats! 4) Make sure your cat gets plenty of exercise and play time. You may even want to give your cat some extra exercise and playtime to help burn a little more of that fat and those calories!

Some cats enjoy chopped iceberg lettuce. You may want to try putting out a plate of chopped lettuce and see if your cat ‘bites’. If he/she does this may be an excellent diet-time treat!

Precautionary measures:

It is easiest if your cat never gets overweight in the first place so try to keep your cat at a healthy weight at all times. Feed him/her a high quality, low-calorie, high-fiber food and make sure that your cat gets plenty of exercise.