Mast cell tumors are skin tumors on dogs and cats that can be serious, depending on the grade of tumor. While any dog can develop a mast cell tumor, the most common breeds to develop one are: boxer, the Rhodesian ridgeback, the pug, the Boston terrier, the pit bull terrier, the Weimaraner, and the shar-pei. Those breeds are 4-8 times more likely to develop a mast cell tumor.
There are multiple kinds of different tumors. The way that we find out which type of tumor is present is doing a fine needle aspirate. We use a needle and stick it into the tumor. After that we spread the cells received on a slide, stain them, and look at it under the microscope. The cells we see under the microscope will let us know what kind of tumor is present. Once stained, mast cells have the appearance of tiny granules scattered in the cell and all around the cytology. See image below.
Mast cells are "graded" on a scale of I-III. I being the 'best' form of a mast cell to have. III meaning the mast cell is more aggressive. All mast cells should be taken off no matter what grade they are.
When we remove tumors we like to send them to our lab to get a grade and prognosis of the tumor. It is important to get this information so we can know what to expect in the future. You should check your dogs and cats frequently for any masses. If you notice one that has come up, it's best to get it checked out! It could be something as simple as a mass of fat, but could also be something like a mast cell tumor.