This lecture will cover many frequently asked questions regarding canine mast cell tumors. This will include discussion on interpretation of grade on histology, proper usage and interpretation of the canine mast cell tumor prognostic panel, determination of surgical margins pre-operatively, patient selection for STELFONTA® (tigilanol tiglate injection), and the chemotherapy treatment options recommended for canine mast cell tumors. We will also include evaluation for patients with multiple mast cell tumors and their treatment approach. A question and answer period will also be utilized with the lecture.