Recently a vaccine has been released for use in the treatment of stage II/III oral melanoma. The studies on the efficacy of this vaccine show significantly prolonged survival times in dogs with local tumor control (no active gross disease) and no metastatic disease. Dogs receiving the vaccine with local tumor control have median survival times approximately twice as long as those with active disease.
Treatment:

The primary treatment for dogs with an oral mass usually consists of an excisional biopsy with wide margins. In addition to a histological diagnosis, the following information is helpful prior to immunotherapy:

1. Prior to excision measure the size of the mass and note it in your records. The WHO staging scheme for dogs with oral melanoma is primarily based on size, with stage I = < 2 cm. diameter tumor, stage II = 2 cm. to < 4 cm. diameter tumor, stage III = 4 cm. or greater tumor and/or lymph node metastasis and stage IV = distant metastasis.

2. Clinical staging of dogs with melanoma includes:

• Through history and physical exam,
• Complete blood count & platelet count, biochemical profile, and urinalysis
  

3 view chest films

• Local lymph node aspiration (ipsilateral and contralateral nodes for oral melanoma due to variability in draining patterns) with cytology whether lymphadenomegaly is present or not.

Once a diagnosis of melanoma has been made and distant metastatic disease has been ruled out the vaccine protocol can be initiated. A second more extensive surgical procedure is recommended if clean margins were not achieved with the original procedure. The surgeons at SOVSC are prepared for potentially large resections that may require partial mandibulectomy or maxillectomy. These cases often require extended hospital stays with aggressive nutritional and analgesic support post-operatively.

In cases where clean margins are not able to be achieved radiation therapy should be considered in combination with vaccine therapy. In cases where radiation is not an option, appreciable reduction (approximately 25%) in tumor size can be achieved with vaccine therapy alone.
Vaccine information

Side effects of the vaccine have not been observed at SOVSC, however transient fever and pain at the injection site have been reported. The vaccine is administered intradermally every 2 weeks for 4 treatments, followed by boosters every 6 months.
The melanoma vaccine has currently only been conditionally released and is only available at veterinary referral centers, such as SOVSC, so if you have any questions regarding this disease and possible vaccine therapy for one of your patients please contact us. The medical and surgical teams at SOVSC work together on cases such as these to provide the most comprehensive care of you clients.

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