When Linda and Patrick Henthorne took their chow, Tory, into a routine dental checkup in 2012, they didn’t expect to find out that she had oral melanoma.
Before the checkup the Henthornes suspected something may be wrong, since Tory’s breath had been abnormally strong, but they didn’t foresee such bad news. Tory, the Henthornes only pet, was 5 years old at the time.
Because melanoma is a cancer of the pigment-producing cells of the body (melanocytes), canine oral melanoma is more common in dogs with darkly pigmented gums, cheeks and tongues. These breeds include chows, poodles, dachshunds, Scottish terriers and golden retrievers, among others. Aside from foul breath, other symptoms a dog with oral melanoma may exhibit include:
- Increased salivation
- Facial swelling
- Bleeding in the mouth
- Difficulty swallowing, and
- Weight loss
The next step for the Henthornes was to take Tory to The Ohio State University College of Veterinary Medicine to have her evaluated. After confirmation of the cancer, Tory soon underwent surgery, performed by Drs. Lillian Su and Christopher Adin.
The procedure was successful in removing the cancer from the back, left-side of Tory’s tongue as well as a lymph node on the same side. Over the next several months she had four radiation treatments, and shortly after her cancer went into remission.
“Tory had frequent check-ups and after six months, the vets didn’t see anything recurring in her mouth or lungs,” Linda Henthorne said. “We weren’t sure we were out of the woods, but they weren’t seeing any changes that would indicate otherwise.”
Luckily, treatment options for Tory didn’t stop there. In 2010, a human DNA-based vaccine for canine oral melanoma was approved by the Food and Drug Administration. This vaccine, a form of immunotherapy, uses the body’s own immune system to control the growth of tumors. It contains the human DNA sequence encoding an enzyme called tyrosinase, which is critical to the survival of melanocytes. The dog’s immune system sees the human tyrosinase as foreign, triggering it to recognize the tyrosinase present in cancer cells as foreign. The body responds by destroying the human tyrosinase as well as the tyrosinase present in cancerous melanocytes, rendering them incapable of surviving. Tory received this vaccine every two weeks for several months.
Unfortunately Tory started to lose functionality of her tongue last year, Linda said, adding that they have been hand-feeding her to make sure that she gets enough food. The Henthornes also administer subcutaneous fluids to Tory twice a week, since she has a hard time drinking water, but daily snacks of Knox gelatin help keep her hydrated. Veterinarians think the loss of tongue functionality is due to delayed radiation effects.
Overall, Linda Henthorne is very pleased with what veterinarians at Ohio State has been able to do for Tory, as her quality of life remains high.
“They did a great job; it saved her life,” Linda said. Her statement is no exaggeration considering that on average, even the mildest stage of oral melanoma – if left untreated - will take the life of a dog within a year. “They gave us as much information as we possibly could have consumed during the process, and were happy to meet and talk with us as we needed.”
March 17, 2016