Melanoma

Melanoma is the most common oral malignancy in dogs, with the haired skin being the most common site. Primary melanomas can occur in various anatomical locations, including the nailbed, footpad, eye, gastrointestinal tract, nasal cavity, anal sac, or mucocutaneous junction. Metastatic sites often include lymph nodes and lungs, but other secondary sites such as the liver, meninges, and adrenal glands are also reported. Overrepresented breeds include Scottish terriers, golden retrievers, Chow Chows, poodles, and dachshunds. Melanomas arise from melanocytes, which can dedifferentiate and resemble various cell lineages, making definitive diagnosis challenging. Immunohistochemistry often aids in diagnosis. Canine melanomas exhibit diverse behaviors based on anatomical site, size, stage, and histological characteristics. Oral melanomas with a mitotic count ≥4/10 hpf are highly aggressive, capable of infiltrating bones and spreading to the lungs, while those with a mitotic count