Amelanotic melanoma in dogs: signs, diagnosis and next steps

Melanomas arise from melanocytes, the cells associated with pigment. An amelanotic tumour can appear pink, red, pale or flesh-coloured because it contains little obvious melanin. Colour alone therefore cannot identify or exclude melanoma. In dogs, these tumours can occur in the mouth, around a nail or on haired skin, and their behaviour varies with their site and microscopic features.

A veterinarian may take cells with a needle or collect a biopsy. A pathologist examines the sample and may use special stains to establish melanocytic origin when routine microscopy is inconclusive. The report can also describe cell division, invasion and whether an excised mass reaches a cut edge.

Arrange a veterinary appointment for a new or changing lump, an oral growth, persistent mouth bleeding, difficulty eating, a damaged-looking nail or unexplained lameness. Photograph an external lesion beside a familiar object and record when you first noticed it, but do not squeeze, cut or treat it with a human skin product.

If testing confirms melanoma, the veterinarian may assess nearby lymph nodes and other body areas before recommending care. Surgery is often considered when a tumour can be removed, while additional treatment depends on location, spread, pathology findings and your dog's general health. A veterinary oncologist can explain whether specialist imaging or systemic treatment is appropriate.

Seek prompt veterinary care if a mass bleeds repeatedly, grows noticeably, becomes ulcerated or interferes with eating or walking. Contact an emergency veterinary service if your dog has trouble breathing, cannot control active bleeding, collapses or suddenly becomes very weak. These signs require assessment regardless of the suspected cause.

Ask which test will confirm the mass, whether special pathology stains are needed, what the report says about surgical edges and aggressive features, and whether lymph-node sampling or imaging would change the treatment plan. Also ask how to protect the biopsy or surgery site and which changes should trigger an earlier recheck.