Canine melanoma occurs in the melanocytes, or pigment producing cells of the skin. Many breeds appear to be prone to this type of cancer, and vets believe there may exist a genetic vulnerability to the illness. The cancer can be more or less aggressive, depending where it appears on the body.
Risk Factors for Canine Melanoma
Melanoma occurs most often in pets aged nine to twelve years. Black dogs and male dogs appear more prone to this type of cancer.
Some breeds appear to succumb to melanoma more often than others. They include:
- Scottish Terrier
- Golden Retriever
- Poodle
- Dachshund
- Chow Chow
- Airedale Terrier
- Boxer
- Springer Spaniel
- Irish Setter
- Doberman Pinscher
Symptoms of Melanoma in Dogs
Canine melanoma causes tumors to appear on the skin. Places where tumors appear most commonly include on or between the toes and in the mouth. The tumors may be black in color, or may be the same color as your dog's skin.
Dogs who develop melanoma tumors of the skin may experience individual growths that appear on the face, feet and toes, scrotum and torso. Dogs who develop melanoma tumors in the mouth may also experience bad breath, drooling and swelling of the face. They may bleed from the mouth and have trouble eating.
In advanced cases, this cancer may spread to the dog's lungs, causing breathing difficulties.
Diagnosing Canine Melanoma
Your vet will perform a number of tests to assist in the diagnosis of canine melanoma. A urinalysis, complete blood count and biochemical profile can give your vet detailed information about your dog's overall health.
Your vet will need to perform a biopsy on any tumors in order to determine if they are indeed cancerous, since many dogs develop non-cancerous tumors of the skin. Your vet will use a very fine needle to remove cells from the tumor; these cells can then be examined in a laboratory to determine if they are normal. If your vet determines that the tumors on your dog's skin or in his mouth are cancerous melanomas, then he'll take X-rays and ultrasounds of the chest and abdomen to see if the cancer has yet spread.
Treating Skin Cancer in Dogs
The best treatment for canine skin cancer is to remove the tumor. Your vet will also want to remove a large part of the healthy tissue surrounding the tumor, to help ensure that the cancer doesn't come back. If your dog has a melanoma tumor on one of his toes, the entire toe may need to come off. If your dog has an oral melanoma, a substantial part of his jaw may need to be removed.
If your dog's tumors can't be surgically removed, due to their location or because they have already spread, then your vet will recommend chemotherapy. Your vet may recommend these drugs even if he manages to remove all of the cancer, in order to keep the cancer from coming back. Aggressive surgery can greatly increase your dog's chances of surviving this type of cancer.