Cats should look like a straight line from above and the sides. If you cannot find ribs, but can grab handfuls of fat, it is time to consider a weight loss program. Obesity is a frightening disease, because, in addition to causing serious discomfort and body dysfunction, it exacerbates other diseases. Obese animals may have trouble breathing. Obese animals with heart or lung disease can have deadly trouble.
Arthritic animals undergo needless discomfort when carrying extra fat around.
Obesity is known to cause liver disease, hypertension, constipation, heat intolerance, and increased risk under anesthesia. With all these problems, it is easy to see why obese animals do not have normal life expectancies. In addition, lean animals have better immune system function and don't form tumors as readily. It is also advisable to have your veterinarian perform a physical exam first and to start slowly, just as with people. Many veterinarians recommend commercial weight loss diets, and some of these work so well that they are available only by prescription.