Cancer is one of the common problems we see in our middle age and geriatric patients. The most common is mammary gland (breast) cancer which, incidentally, is very rare in dogs and cats spayed prior to their first heat cycle. This is one reason we recommend spaying at six to seven months of age. Other common cancers include lymphomas, lymphosarcoma, mast cell tumors, bone tumors, peri-anal adenomas and adenocarcinomas of various glandular structures such as the colon.
Where possible, we always prefer surgical removal of the tumor with pathology to determine the completeness of removal. We also use various chemotherapy protocols and drugs depending on the tumor type. Fortunately, chemotherapy does not cause many of the side effects, such as nausea and vomiting, seen in human patients. Surgical and chemical treatment can add months, and sometimes years, to the life of the veterinary cancer patient.
Some breeds of dogs are more likely to get certain cancers than others. The Boxer is the breed most commonly affected by cancer. We see many types of cancer in Boxers the most common being the malignant mast cell tumor. Golden Retrievers, especially older dogs, commonly have a malignant bone tumor call Osteosarcoma requiring amputation of the affected limb.