Mast cell tumors, known as mastocytomas, develop commonly in the skin. There is no known cause for why your dog develops a mast cell tumor. Mast cell tumors are the most common type of tumors in dogs.
Mast cell tumors typically appear as raised and round masses in the skin. The tumor is larger then it appears in most cases. Surgery is necessary to remove the tumor and large margins of normal looking tissue has to be removed along with the mast cell tumor.
A mast cell tumor generally appears on the skin. However, the mast cell tumor can metastasize to the liver, gastrointestinal tract, spleen and blood stream.
Grade 1 mass cell tumors can be completely removed surgically and prognosis is excellent. Grade II tumors can spread but be managed medically and your dog would have a 50 percent chance of survival for over 4 years. Grade III tumors have a poor prognosis with less than 10 percent of dogs surviving for a 4 year period.
Mast cell tumors release histamine when stimulated. This can cause your dog to suffer from hives from an allergic reaction to the histamine and it also increases stomach acid production.
Mass cell tumors in your dog can cause stomach ulceration and itchiness after surgery or during treatment. In rare cases, anaphylaxis, a severe and sometimes fatal allergic reaction can occur.
If your dog has been diagnosed with stage III, chemotherapy and radiation is an option. It is not a cure and is used to make your dog more comfortable and to improve and prolong his quality of life.