The first cancer treatment drug specifically designed for dogs has been approved by the FDA. The drug has been named Palladia, a word which has roots to classical mythology and the goddess Pallas, who is associated with protection.
Palladia, manufactured by Pfizer Animal Health Inc, has been found to successfully treat mast cell tumors by cutting off the blood supply to them, thus preventing metastasis to other parts of the body, including the lymph system, which can occur with this form of canine skin cancer. The drug can be used effectively with or without lymph node involvement. 
Mast cell tumors account for about 20 percent of canine skin cancer. They are usually seen as solitary lumps or masses in or under the skin, but can occur in a wide range of sizes and appearances. Currently, surgical removal has been the primary method of treatment. However, because of their locally invasive behavior, wide margins of what appears to be normal tissue around the tumor need to be removed to increase the likelihood that the tumor has been completely removed.
The Boxer is at an especially high risk for mast cell tumors, as are related breeds like the English Bulldog and Boston Terrier. Also at higher than average risk are the Shar Pei; Labrador Retriever; Golden Retriever; Schnauzer; and Cocker Spaniel.
Palladia, a tyrosine kinase inhibitor, works on individual tumor cells to kill these abnormal cells. It also acts on the blood vessels that supply the mast cell tumor(s). It is meant to be used for dogs with recurrent tumors and those staged as grade II or III. Possible side effects include: depressed appetite or refusal to eat; vomiting; diarrhea; fresh blood in vomit or feces; dark, tarry feces; or abnormal or unexplained bruising or bleeding.
Pfizer is scheduled to begin selling Palladia in early 2010. If your dog is covered by pet health insurance, you can expect the terms of coverage to be similar to existing treatments. Jennifer Neal, spokeswoman for Pets Best Insurance, advises that its policies pay 80 percent of the cost after the deductible, up to the per-incident limit. Per-incident limits vary per policy. Neal said the cost for existing cancer treatments seldom exceeds $6,000. She also suggested that pet owners purchase insurance when their pets are young, since pre-existing conditions are not covered.