Melanoma and Moles in Dogs: Identification and Treatment Guide

Most people have at least one mole, and dogs commonly have pigmented lumps or spots too, often hidden under their fur. While most moles in dogs are benign, like human moles, they can occasionally become malignant. Getting familiar with your dog’s skin through regular grooming and examination helps you detect changes early, improving treatment outcomes.

In this guide, you will learn what melanoma is, why some moles turn malignant, how to spot warning signs, which breeds are most at risk, and the best approaches to treatment.

What is Melanoma in Dogs?

Melanoma is a form of cancer that arises from melanocytes, the pigment-producing cells in skin and hair. In dogs, melanomas can be either benign (non-cancerous) or malignant (cancerous). Around 90% of skin melanomas in dogs are benign and called melanocytomas, but malignant melanomas, especially oral and digital types, can be aggressive and life-threatening.

Types of melanoma include:

• Cutaneous (skin) melanomas – usually benign and found under the fur.
• Oral melanomas – malignant, found in the mouth, often aggressive.
• Digital melanomas – affect toes or nail beds, often malignant.
• Ocular melanomas – affect the eyes.

Early detection is vital, as malignant melanomas can spread to internal organs like lungs and liver.

Why Do Some Moles Become Malignant?

While the exact cause is unclear, certain factors increase risk for melanoma:

• Breed predisposition: Some breeds like Chow Chows, Golden Retrievers, and Pekingese/Poodle mixes have higher oral melanoma risk. Breeds like Rottweilers and Labrador Retrievers may be more prone to digital melanoma.
• Age: Older dogs (usually 9+ years) are more susceptible.
• Genetics: Inherited factors play a significant role.
• UV exposure: Unlike humans, sun exposure is generally not a major risk for melanoma in dogs, although lighter-skinned or hairless dogs may have some increased vulnerability.

Other possible influences include hormonal changes, immune system health, and environmental toxins, but research is ongoing.

How to Identify Problematic Moles

Familiarity with your dog’s normal skin condition is key. Regularly groom and part your dog’s fur to check for moles or skin changes. Watch for these signs that a mole might be malignant:

• Change in texture – roughening after being smooth.
• Hair growth from a previously hairless mole.
• Raised appearance of a mole that was flat.
• Darkening or other colour changes.
• Increase in size or width.
• Irregular or blurred edges.
• Bleeding, discharge or crusting.

If you notice any such changes, have your vet examine your dog promptly. Changes don't always indicate cancer, but they need evaluation.

Treating Melanoma Moles in Dogs

If melanoma is suspected, the vet will conduct a thorough examination and usually take a biopsy for a definitive diagnosis. Early-stage melanomas detected in time often can be surgically removed successfully.

Advanced melanomas that have spread may require more complex treatment, including chemotherapy, radiation, or immunotherapy. Treatment decisions depend on the melanoma type, size, location, and whether the cancer has metastasised.

Regular veterinary check-ups and early detection improve prognosis. Preventive care includes avoiding unnecessary shaving that exposes skin, protecting lighter or hairless breeds from sun exposure, and monitoring moles consistently.

Summary and Responsible Ownership

Most moles in dogs are harmless, but vigilance is essential to catch malignant melanoma early. Older dogs and certain breeds face higher risks. Regular checks and prompt vet visits for mole changes are crucial steps in responsible pet care.

Educating yourself about melanoma empowers you to protect your dog’s health effectively and compassionately.