Veterinarians cannot do much to prevent cancer in cats but they can often treat it.  If your cat is older and doesn’t seem to be well, your veterinarian will probably test for cancer among other diseases.  How common is cancer in cats? Dr. Janice Baxter, Veterinarian at the Alexandria Animal Hospital in Virginia says that cancer is not uncommon in older cats.  This is because the general cat populations are living longer and longer. She says that a diagnosis of cancer is no longer necessarily a death sentence.  Surgery, Chemotherapy and pet medication can help many cats, but the financial costs are high. If your cat is older, is losing weight, not eating or is listless, have him checked out by your vet right away. Delaying treatment could be life threatening!