Mammary gland cancer. Mammary gland or breast cancer is common in both dogs and cats. It is the most common tumor found in female dogs and the third most common in cats.
Lymphoma. Lymphoma is an incurable cancer of the lymph system, which is part of the immune system. In cats, one in three cancer diagnoses is lymphoma, most often of the GI tract. Dogs also develop lymphoma. To avoid contributing to your dog’s or cat’s lymphoma risk, make sure your pet isn’t exposed to cigarette smoke or lawn pesticides, especially those applied by professional lawn care companies.
Mast cell tumors. The most common type of skin cancer in pets is mast cell tumor (MCT). MCT is much more prevalent in dogs than in cats. In cats, mast cell tumors are most often seen in the skin of the head or neck, but they can occur anywhere in the body. Cats with these tumors are usually middle-age or older. In dogs, mast cell tumors are most often found on the trunk, limbs, and in between the toes. Prognosis depends on the tumor location, the extent of the tumor, the grade, and the type of treatment given. Mast cell tumors of the skin are very different in dogs than cats.
Bone cancer (osteosarcoma). Osteosarcoma is a common and aggressive bone cancer that invades the long bones of large and giant breed dogs. Even with amputation of the affected limb and chemotherapy, which is the current standard of treatment, the average survival rate is only about a year.