Behavior
Melanomas that occur in hairy places are usually not malignant, in contrast to those on the transition between skin and mucous membrane. Benign melanomas of the skin are well defined, highly pigmented, small and mobile. Malignant skin melanomas look bigger (> 2.5 cm), grow quickly and can ulcerate. Metastases occur through both the blood and lymphatic systems.
Melanomas that occur on hairy skin make up 5-7% of all skin tumors in dogs. These tumors arise from pigment cells in the epidermis, dermis, structures closely associated with the skin, but mainly arise from the hair follicles.
Prevalence
This tumor type affects mainly dogs between 5-11 years of age (average age 9 years).
Breed predisposition
The following breeds were reported to be at higher risk to develop this tumor type: i.a. Airedale Terrier, Boston Terrier, Cocker Spaniel, Miniature Schnauzer, Doberman Pinscher, Scottish Terrier, Vizsla.
Symptoms
Skin melanomas vary in their appearance. Generally, a melanoma forms one solid lump, and the color of the melanoma can take on a variety of colors, ranging from black to shades of brown, gray, and red.