Melanoma in dogs and cats poses significant clinical challenges for veterinary practitioners. This guideline aims to consolidate available knowledge into a comprehensive resource to support clinical decision-making. Melanocytic tumors are common in dogs but rare in cats. Oral and subungual malignant melanomas are the most prevalent in dogs, while many tumors are heavily pigmented, making diagnosis relatively straightforward. A validated clinical staging scheme exists for canine oral melanoma, and TNM-based staging applies to other locations and feline melanomas. Prognostic factors include location, mitotic index, and presence of intratumoral necrosis. Surgical resection with wide margins is the primary treatment for local control, and radiotherapy is integral for canine oral melanomas. Adjuvant immunotherapy or chemotherapy is offered to high-risk patients. The guideline emphasizes the importance of accurate diagnosis, staging, and appropriate treatment planning, including the use of advanced imaging techniques and immunohistochemistry.Melanoma in dogs and cats poses significant clinical challenges for veterinary practitioners. This guideline aims to consolidate available knowledge into a comprehensive resource to support clinical decision-making. Melanocytic tumors are common in dogs but rare in cats. Oral and subungual malignant melanomas are the most prevalent in dogs, while many tumors are heavily pigmented, making diagnosis relatively straightforward. A validated clinical staging scheme exists for canine oral melanoma, and TNM-based staging applies to other locations and feline melanomas. Prognostic factors include location, mitotic index, and presence of intratumoral necrosis. Surgical resection with wide margins is the primary treatment for local control, and radiotherapy is integral for canine oral melanomas. Adjuvant immunotherapy or chemotherapy is offered to high-risk patients. The guideline emphasizes the importance of accurate diagnosis, staging, and appropriate treatment planning, including the use of advanced imaging techniques and immunohistochemistry.