Mast cell tumor in dogs – on the side
By Joel Mills [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons
Mast cell tumor in dogs – inner thigh
By Joel Mills (Own work) [ CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons
Mast cell tumor in dogs – on the lip
By Joel Mills [ CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons
Mast cell tumor in dogs – toe
By Joel Mills (Own work) [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons
See also Mast Cell Tumors in Dogs: Symptoms, Treatment and Prognosis