Melanocytes are cells located in the basal layer of the skin’s epidermis that produce melanin, the pigment that is found in the skin, eyes and hair. Melanoma is a malignant cancer or tumor of melanocytes.
Canine melanoma is a condition of inordinate multiplication of cells that produce pigments. Predominantly seen as skin cancer, it can also affect melanocytes in the bowel and the eye. Canine melanoma is a potentially fatal condition, as it progresses rapidly and leads to multiple tumors once it appears in an organ.
Melanomas account for approximately 4 to 6 percent of all skin cancer in dogs. The most common areas that are affected are the toes and mouth. The cancer may eventually spread to the lymph nodes and lungs. Melanomas are characterized by irregular brown or black skin lesions with shades of red, white or blue. Skin lesions can be seen easily in the toes. If it is a case of oral melanoma, excessive salivation, offensive mouth odor, weight loss, blood in the mouth, difficulty eating, and loose teeth are evident symptoms that can be noticed.
Diagnosis involves palpation of the lymph nodes and a complete laboratory examination of a blood sample. Oral melanoma usually leads to secondary infections, and the blood report is likely to indicate an abnormal rise in the white blood cell count. As the common site for metastasis is the lungs, a chest X-ray helps in determining the level of spread of the cancer. A biopsy for examining cancerous tissue may prove helpful in treatment since it can identify locations of cancerous and healthy tissues. A biopsy can lead to an effective removal of the tumor and adjoining healthy tissues. In a third of the cases, the specimens do not contain melanin. This compels the veterinarian to aspirate from lymph nodes or remove one or more lymph nodes for confirming metastasis.
Despite intensive laboratory and clinical research, the single effective cure is a surgical removal of the primary tumor before it achieves a thickness greater than 1 mm. If there is no evidence of metastasis and the cancer has invaded the jaw, the jaw bone may need to be removed as well. Radiation may be advised for reducing the size of the tumor.
Chemotherapy is not advisable, as it has been found to be ineffective where metastasis of melanoma has occurred. A homeopathic cancer treatment for dogs can provide symptomatic treatment and make life comfortable for the dog for as long as he lives.
Risk factors for canine melanoma are not clearly defined. While in humans excessive exposure to the sun’s ultraviolet rays is know to induce melanoma, in dogs this is not a major risk as in most breeds the dog’s coat provide sufficient protection from sunlight. There seems to be an element of inheritance involved in development of canine melanoma and research is currently being undertaken to develop genetic therapies to stimulate the immune system to combat tumor cells.