Melanomas in Dogs: Causes, Symptoms, and Treatments

Melanomas in dogs are tumors from melanocytes, the cells responsible for the pigment in the skin and hair. The tumors are benign (non-cancerous) or malignant (cancerous). The causes of melanoma in dogs include genetic predispositions, UV radiation exposure, and immune system abnormalities. Symptoms of dog melanoma vary depending on the stage and location of the tumor. Pet owners must prioritize early detection and regular check-ups to assess the dog's skin for changes. Diagnosing melanoma dogs involves physical exams, biopsies, imaging studies, and staging. Treatment options for melanoma cancer in dogs include surgical removal, chemotherapy, radiation therapy, and immunotherapy using DNA vaccines.

What are Melanomas in Dogs?

Melanomas in dogs are malignant tumors that arise from melanocytes, the cells responsible for skin pigment. The tumors develop in the dog's body, including the oral cavity, nailbed, mucocutaneous junctions, and eyes. “Canine melanoma is a locally invasive tumor found in the mouths and digits of dogs, with a high rate of metastasis,” according to the report by the National Cancer Institute titled “Canine Melanoma,” 2020. 

Dogs with melanomas exhibit symptoms like changes in pigmentation, ulceration, bleeding, or growth. Biopsy, the removal of a small tissue sample for examination, is necessary to confirm a diagnosis. Staging determines the extent of the tumor's spread and assists in planning an appropriate treatment strategy. Surgical removal of melanoma, radiation therapy, or chemotherapy are recommended based on the tumor's size and location.

How do Melanomas in Dogs Work?

Melanomas in dogs work by forming locally invasive tumors or metastasizing to sites such as the lymph nodes. The tumors impact normal cell function and lead to complications. Melanoma in dogs manifests in various forms and stages. “Staging for Canine Oral Malignant Melanoma should include blood work (complete blood count and serum biochemistry profile), urinalysis, assessment of regional lymph nodes, and imaging of the thoracic cavity,” according to the report by Meyer, B. & Martin, O., titled “Diagnosis and Treatment of Canine Oral Melanoma,” 2021.

Melanoma starts when melanocytes undergo mutations in their DNA, causing them to grow and multiply uncontrollably. The mutated cells form tumors in the skin, mucous membranes, or other tissues where melanocytes are present. The cells produce melanin that gives skin its color. 

Melanoma evades the body's natural defense mechanisms. It starts replicating and forms a tumor. The tumor disrupts the surrounding tissues and interferes with crucial bodily functions. The tumor infiltrates neighboring structures, depending on the aggressiveness of the melanoma.

Four stages classify melanoma in dogs. Localized melanoma characterizes Stage 0. A small tumor confined to the skin or mucous membranes defines Stage I. Stage II marks the tumor's growth, invading nearby tissues. The cancer spreads to nearby lymph nodes in Stage III, while Stage IV indicates metastasis to distant organs.

Is Melanoma Cancer in Dogs?

Yes, melanoma is cancer in dogs. Melanomas are classified as cancerous growths due to their malignant nature and high spreading tendency. “Canine malignant melanoma (CMM) is a common and aggressive form of cancer in dogs,” according to the study by Gyorffy, S., Rodríguez-Lecompte, J., Woods, J., Foley, R., Kruth, S., Liaw, P., & Gauldie, J. titled “Bone marrow-derived dendritic cell vaccination of dogs with naturally occurring melanoma by using human gp100 antigen,” 2005.

Melanoma is a cancer that impacts a dog's overall health and quality of life. Malignant melanoma in dogs metastasizes to other body parts, reducing survival rates. Some breeds are genetically predisposed to developing melanomas, while exposure to UV radiation contributes to its manifestation. Dog owners must regularly check their pets for unusual growths or skin changes that indicate the presence of melanoma.

Can Melanomas in Dogs Lead to Tumors?

Yes, Melanomas in dogs lead to tumors. Melanomas are tumors originating from melanocytes, specialized cells in the skin responsible for producing pigment. The tumors grow and develop into larger masses if left untreated. Melanoma is one of the most common types of oral tumors in dogs. 

Aggressive tumors infiltrate surrounding tissues and metastasize to other body parts. “Melanoma in dogs can lead to tumor, as seen in a case of a 7-year-old Rottweiler with multiple esophageal metastases,” according to the study by Tăbăran, F., Nagy, A., Bolfă, P., Gal, A., Boari, C., Borza, G., & Catoi, C. titled “A case of disseminated melanoma with esophageal metastasis in a dog,” 2012.

What are the Symptoms of Melanomas in Dogs?

The symptoms of melanomas in dogs are listed below. 

• Visible skin changes: Melanomas appear as darkly pigmented or raised masses on the skin. The small masses are black, brown, or red and grow over time.
• Changes in existing moles or skin pigmentation: Changes in size, shape, color, or texture of existing moles on the dog’s body indicate melanoma.
• Ulceration or bleeding: Melanomas ulcerate, causing the skin over the tumor to break open or bleed, leading to scabbing or crusting over the affected area. Dog mole bleeding is a sign of melanoma.
• Limping or lameness: Melanomas occur on or under the toenails or footpads, leading to pain, limping, or lameness. Dogs lick or chew at the affected paw.
• Difficulty eating or swallowing: Oral melanomas affect the mouth, gums, tongue, or throat, making it painful for dogs to eat, swallow, or open their mouth comfortably.
• Bad breath: Oral melanomas cause halitosis (bad breath) due to infection or tissue decay in the mouth.
• Changes in behavior: Some dogs become more irritable, lethargic, or reluctant to play if they are in pain or discomfort due to melanomas.

How are Melanomas Diagnosed in Dogs?

Melanomas in dogs are diagnosed through physical exams, biopsies, imaging studies, and staging to determine the extent of the disease. Biopsy results confirm the presence of melanoma. “Canine melanocytic neoplasms can be accurately diagnosed and prognosticated through surgical biopsy, with immunohistochemical labeling and RNA expression analysis being crucial for accurate differentiation and prognosis,” according to the study by Smedley, R., Sebastian, K., & Kiupel, M. titled “Diagnosis and Prognosis of Canine Melanocytic Neoplasms,” 2022.

Veterinarians perform a physical examination to assess the suspected melanoma's size, location, and characteristics. X-rays, ultrasound, or CT scans help visualize internal structures and detect tumor spread. Staging determines the severity of the melanoma and planning appropriate treatment. Staging involves evaluating the cancer's size, depth, and metastasis to lymph nodes or other organs. 

What Causes Melanomas in Dogs?

The causes of melanomas in dogs are listed below. 

• Genetics: Certain breeds of dogs are predisposed to developing melanomas, indicating a genetic component to the disease. The ‘Chow Chow, Golden Retriever, and Pekingese/Poodle mix breeds were overrepresented in canine oral melanomas, while Boxer and German Shepherd breeds were underrepresented,“ according to the study by Ramos-Vara, J., Beissenherz, M., Miller, M., Johnson, G., Pace, L., Fard, A., & Kottler, S. titled “Retrospective Study of 338 Canine Oral Melanomas with Clinical, Histologic, and Immunohistochemical Review of 129 Cases,” 2000. 
• UV radiation exposure: Excessive exposure to sun ultraviolet (UV) radiation increases the risk of melanoma development in dogs. Dogs with lighter skin or hair pigmentation are at higher risk, as they have less natural protection against UV radiation.
• Age: Melanomas are more common in older dogs, though they occur at any age.
• Hormonal factors: Hormonal imbalances or fluctuations influence the development of melanomas, though the exact mechanisms are not well understood.
• Immune system dysfunction: Dogs with weakened immune systems due to underlying diseases or medications suppressing the immune response are at higher risk for developing melanomas.
• Environmental factors: Exposure to environmental toxins or carcinogens increases the risk of melanoma development, though specific links have not been established.

How Common are Melanomas in the Mouth of Dogs?

Melanomas in the mouth of dogs are relatively common, with the oral cavity being a frequent location for these tumors to develop. “Melan A is a specific and sensitive marker for canine oral melanomas, detecting them in 92.6% of oral and 5/7 metastatic cases with the gingiva and labial mucosa being the most common sites,” according to the study by Ramos-Vara, J., Beissenherz, M., Miller, M., Johnson, G., Pace, L., Fard, A., & Kottler, S. titled “Retrospective Study of 338 Canine Oral Melanomas with Clinical, Histologic, and Immunohistochemical Review of 129 Cases,” 2000.

Melanomas in dogs appear as dark, raised lumps or masses on the skin that vary in size and number. The coloration ranges from dark brown to black, resembling moles or warts. Melanomas are common in areas with less hair coverage, such as the abdomen, groin, or paw pads.

Are Melanomas Caused by Food Allergies?

No, melanomas are not caused by food allergies. There is no direct evidence linking melanomas in dogs to food allergies as a primary cause. Melanomas are associated with factors such as genetic predispositions and environmental influences. Dog food allergy in dogs is an immunological reaction. “Ultraviolet radiation exposure, geographical location, and individual factors contribute to the risk of cutaneous melanoma, with new biomarkers potentially improving prevention and treatment effectiveness,” according to the study by Volkovová, K., Bilaničová, D., Bartoňová, A., Letašiová, S., & Dusinska, M. titled “Associations between environmental factors and incidence of cutaneous melanoma. Review,” 2012.

Can Canine Melanomas Spread to Humans?

No, canine melanomas cannot spread to humans. The tumors are specific to dogs and do not pose a risk of transmission or spread to humans. “Canine melanoma is not zoonotic, but it is a devastating disease with variable histologic and cytologic patterns,” according to the study by Smith, S., Goldschmidt, M., & McManus, P. titled “A Comparative Review of Melanocytic Neoplasms,” 2002. 

Melanomas in dogs and humans are diseases with different causes that share similarities in biological behavior and appearance. “Canine melanomas and human melanomas share genetic alterations and pathways, making them a potential predictive preclinical surrogate for human melanoma,” according to the study by Hernandez, B., Adissu, H., Wei, B., Michael, H., Merlino, G., & Simpson, R. titled “Naturally Occurring Canine Melanoma as a Predictive Comparative Oncology Model for Human Mucosal and Other Triple Wild-Type Melanomas,” 2018.

What is the Treatment for Melanomas in Dogs?

Treatment for melanomas in dogs involves surgical removal, chemotherapy, radiation therapy, and immunotherapy using DNA vaccines. “Immunotherapeutic strategies, including monoclonal antibodies, nonspecific immunotherapy activated by bacteria, vaccines, gene therapy, and lymphokine-activated killer cell therapy, show promise in treating canine malignant melanoma,” according to the study by Almela, R., & Ansón, A. titled “A Review of Immunotherapeutic Strategies in Canine Malignant Melanoma,” 2019.

Surgery is the most common choice for localized melanomas in dogs, removing the tumor and surrounding tissue to prevent further growth. Chemotherapy uses drugs to target and destroy cancer cells. Radiation therapy involves high-energy radiation to target cancerous cells while sparing healthy tissue. DNA vaccines are a promising area of research, where a dog's immune system is triggered to recognize and attack melanoma cells, offering a more targeted and effective approach to treatment.

How can Melanomas in Dogs Be Prevented?

Melanomas in dogs can be prevented by minimizing sun exposure, maintaining a healthy diet, and regular veterinary check-ups to detect abnormalities early. 

Preventing cutaneous melanoma in dogs involves limiting sun exposure, especially for dogs with light-colored or thin fur. “Sun exposure plays a significant role in most melanoma tumors, but its role is likely variable and multifactorial, and sun protective measures are prudent,” according to the study by Ivry, G., Ogle, C., & Shim, E. titled “Role of Sun Exposure in Melanoma,” 2006. Providing shade during peak sun hours and using dog-safe sunscreen on exposed areas help shield the dog’s sensitive skin. 

Incorporating nutrient-rich foods like fish, carrots, and leafy greens into the dog’s diet supports a strong immune system to combat cancerous cells. Regular veterinary visits for physical examinations and dietary plans enable proactive response towards contracting melanoma.

Can Melanomas in Dogs Cause Discomfort or Affect Eating?

Yes, melanomas in dogs can cause discomfort and affect eating if the tumors are located in the oral cavity or interfere with normal functions. “Melanomas in dogs can cause discomfort and affect eating, as seen in a 12-year-old Miniature Dachshund dog with osteoid formation affecting the gingiva,” according to the study by Chénier, S., & Doré, M. titled “Oral Malignant Melanoma with Osteoid Formation in a Dog,” 1999. The presence of tumors in sensitive areas like the mouth disrupts normal functions, including feeding. Regular veterinary check-ups and monitoring for changes in appetite enable early detection and intervention in such cases. 

Are There Home Remedies for Treating Melanomas in Dogs?

Yes, there are home remedies for treating melanomas in dogs. Homeopathic treatment of malignant melanoma in a dog involves a holistic approach to stimulating the body's innate healing mechanisms and supporting overall health and well-being. 

Homeopathy is a complementary therapy that helps manage symptoms, improve the dog’s quality of life, and slow the disease’s progression. Complementary therapies like CBD oil manage symptoms and alleviate pain. Professional veterinary care is the preferred route for effective treatment.

Is Papilloma a Type of Gum Disease in Dogs?

No, papilloma is not a type of gum disease in dogs. Papilloma is a benign growth caused by a viral infection that is typically harmless and regresses independently without specific treatment. “Canine papillomas are high-abundance, papillomavirus-infected skin lesions, mainly affecting cutaneous and oral areas,” according to the study by Lange, C., Jennings, S., Diallo, A., & Lyons, J. titled “Canine papillomavirus types 1 and 2 in classical papillomas: High abundance, different morphological associations, and frequent co-infections,” 2019.

Gum disease, or periodontal disease, is a common dental condition in dogs that affects the gums and supporting structures of the teeth. Gum disease in dogs ranges from mild gingivitis to more severe periodontitis and results in systemic health problems if left untreated.

Can CBD Oil Treat Melanomas in Dogs?

Yes, CBD Oil can treat melanomas in dogs. “CBD significantly inhibits melanoma cell growth in vitro at concentrations of 0.2 mg/mL and 0.04 mg/mL, showing potential for inhibiting melanoma cell growth in vertebrates,” according to the study by Burch, R., Mortuza, A., Blumenthal, E., & Mustafa, A. titled “Effects of cannabidiol (CBD) on the inhibition of melanoma cells in vitro,” 2021. 

CBD oil is popular due to its therapeutic benefits in managing symptoms associated with various health conditions in dogs, including melanomas. Research on CBD oil for dogs is ongoing, with some dog owners using it as a holistic supplement to support their pet's well-being.

What is the Life Expectancy for Dog Skin Cancer?

The life expectancy of a dog with skin cancer, including melanomas, depends on factors such as the type and stage of cancer, the effectiveness of treatment, and the dog’s overall health. Regular monitoring and prompt intervention positively impact the prognosis. “Surgical excision of canine melanomas is effective in reducing death rates, but a higher percentage of dogs with malignant skin melanomas die 2 years after surgery,” according to the study by Bostock, D. titled “Prognosis after Surgical Excision of Canine Melanomas,” 1979.

Skin cancer that is detected in its early stages affords better treatment options. The choice of treatment, such as surgery, chemotherapy, or radiation therapy, significantly influences the outcome. The dog's response to a specific treatment and ability to tolerate and recover from therapy contribute to its overall prognosis.