Oral melanoma is one of the most common types of cancer that dogs can develop. In fact, it is believed that oral tumors are the fourth most common type of neoplasms that our canine friends can develop.
There is a breed predisposition, so some dogs are more likely to get this disease. In today’s article, we’re looking at the symptoms, diagnosis, treatment, and prognosis of oral melanoma in dogs.
What dog breeds are more predisposed to developing oral melanoma?
This type of cancer is more common in the following breeds:
Besides this aspect, there is another factor that makes dogs more predisposed to developing this type of neoplasm, and it is their age. Statistically, oral melanoma is far more commonly diagnosed in dogs with ages of approximately 10 to 11 (or older).
Approximately 80% of all cases diagnosed are those of dogs whose tumor has already metastasized to other organs, the most common ones being the lungs and the liver.
Symptoms of Canine Oral Melanoma
Unfortunately, canine oral melanoma can remain asymptomatic for a period of time, which means that dogs are typically not diagnosed in the first stages of the condition.
The cancer can be discovered during routine oral examinations at the vet clinic or while vets are performing a tartar removal procedure.
Some dogs do show clinical signs, and they can consist of the following:
- Increased salivation
- Difficulty in eating or drinking
- Bad breath
- Facial swelling
- Obvious pain when trying to eat or drink
- Visible growths in the oral cavity
If the neoplasm has already metastasized to other organs, the dog’s lymph nodes will be enlarged. Usually, the lymph nodes that become swollen are those located in front of the shoulders or right under the jaw.
Since one of the first organs that this tumor spreads to are the lungs, some dogs might also show respiratory symptoms, such as difficulty breathing, wheezing, or coughing. Lethargy and a loss of appetite are also seen if the tumor has metastasized.
If your veterinarian suspects that your dog has oral melanoma, some of the first tests that they will recommend are going to be general (a complete blood count and biochemistry) to assess your pet’s general health status.
Some melanoma cases can be diagnosed by performing a fine needle aspirate, and since the procedure can cause pain, dogs should be sedated. If the exam is not relevant, your dog might have to be performed a biopsy on, in which case they will have to go under anesthesia.
The difference between these two types of diagnoses is that the biopsy involves the surgical removal of a piece of tissue from the tumor site, whereas the fine needle aspirate simply collects a reduced number of cells from the interior one of the tumors.
These exams focus on discovering the exact type of cancer that the dog has, but also whether it is benign or malignant. If it is malignant, setting the stage of the cancer is important. In stage 1 and tumors that have specific margins, the therapy of choice is most likely to be surgery.
Anything beyond stage 2 involves metastasis, so your dog might have to be performed additional diagnostic examinations on, such as an ultrasound or an X-ray to assess whether the melanoma has spread to the lungs, liver, or any other organs.
When it comes to dog cancer, including oral melanoma, there are three main treatment options that veterinarians can use:
Surgery is mostly performed in cases where the tumor’s margins are very well defined, and the risk of it metastasizing to other organs is quite low.
Chemotherapy is considered to have a rather limited role in the treatment and management of canine oral melanoma. To make matters worse, most melanomas have been found to be somewhat resistant to radiation therapy, which means that the patient will have to receive frequent and repeated radiation treatments.
Moreover, while all of these therapy options cause side effects, the ones involved with traditional chemotherapy are the most significant ones since dogs can experience general malaise and digestive distress in the form of vomiting or diarrhea. Combined with the loss in appetite, this can make a dog’s general health status worse.
However, administering a Merial melanoma vaccine is possible, also in terms of chemotherapy, and it is well tolerated by most patients.
Consistent radiation therapy offers the best results, with most dogs being able to live for more than a year after the treatment has begun. To give you a comparative example, dogs that are diagnosed and whose owners choose to forgo treatment can live for about two to three months.
Combination therapy using surgery, radiation therapy, and the Merial melanoma vaccine that we have mentioned above seem to offer the best results since most dogs live for more than a year and sometimes even two.
How much does the treatment of canine oral melanoma cost? It depends on the therapy that was chosen by the pet owner and veterinarian. For example, surgery can cost anything between $3,000 and $5,000, while radiation therapy (a treatment for 4-6 weeks) can cost $2,000 to $3,000 or more.
Immunotherapy costs an average of $500 per shot, and dogs have to be given a minimum of 4 doses. Chemotherapy costs around $400 to $500 per session (6 treatments, once every three weeks).
Can Oral Melanoma in Dogs Be Prevented?
Unfortunately, there is no way of preventing cancer, in general, in dogs, and oral melanoma, in particular. Your dog might be genetically predisposed to developing this type of tumor, especially if he is part of one of the breeds we have noted at the beginning of this post.
It is unclear just what causes cancer, but environmental factors such as being exposed to carcinogenic substances from food, cleaning supplies, or smoke can contribute to its development.