Gray Horse Melanoma Vaccine Tested

A vaccine designed to target equine melanomas has shown promise in a German study of 27 gray horses, some of which had more than one melanoma. Vaccination with a DNA-based serum induced an immunological response in some other affected species and also in healthy horses, suggesting that the same response might be effective in treating these common skin tumors.

The horses were given a series of intramuscular vaccinations on days 1, 22, and 78. One selected melanoma on each horse was also treated with an injection into the body of the tumor. After 120 days, the tumors showed a significant reduction in volume.

Treatment with the vaccine was considered safe and well-tolerated, though horses developed a significant rise in body temperature on the day after injection.

Melanomas are often found on gray horses, and most are not particularly problematic unless they interfere with tack or become large enough to split, bleed, and attract flies. Surgical removal is not usually a successful treatment.