Canine dermal and subcutaneous mast cell tumors represent up to what percentage of all skin tumors?

• A. 50%
• B. 21%
• C. 10%
• D. 5%

Answer: (B)

Mast cell tumors are one of the most common canine skin neoplasms, representing a substantial portion of dermal and subcutaneous tumors. Across studies, they typically account for about 20–25% of all skin tumors in dogs. The figure around 21% fits nicely within that common range, which is why it’s the best match among the options. While exact percentages can vary with population and breed mix, the key point is that MCTs constitute a notable minority, not a tiny fraction or the majority. Therefore, 21% aligns best with the usual data. The other options over- or underestimate the frequency relative to what most datasets show.