Melanoma is one of the most common oral tumors in dogs. It is associated with a poor prognosis when it arises in the oral cavity, on other muco-cutaneous sites or on the nails. When identified in these sites, melanoma spreads rapidly to the regional lymph nodes and then to lungs and multiple other sites in the body. The diagnosis of melanoma is based on either a tissue biopsy or needle aspirate. As is the situation in people with melanoma, there are limited treatments that have activity and patients with melanoma die because of metastatic disease. Treatment with surgery and/or radiation therapy may help control the primary tumor. Traditionally, because metastases are so common, chemotherapy is recommended. Interestingly, some cases of melanoma respond well to immunotherapy. Multiple investigators have studied a variety of immune-stimulating agents in hopes of improving tumor control. To date, both chemotherapy and anti-melanoma vaccines and other immune-stimulating agents have had limited success. The CCOGC is collecting samples from canine melanoma patients as there is a need for a deeper molecular understanding of the disease to better understand who is at risk, how to prevent it and to devise improved treatments for both dogs and people.