Eastern equine encephalitis, commonly called Triple E, is a disease that affects both horses and humans. So far in 2014, three horses have been stricken in New Jersey and six more have contracted Triple E in New York. At last count, 56 horses have tested positive for Triple E in Florida.

The culprit is a mosquito-borne virus that thrives in the swamps of the Atlantic and Gulf Coast states. The disease targets the nervous system and is rapidly fatal in most affected horses. There is no specific cure, and even horses under intensive care usually die.

Fortunately, a Triple E vaccine is available. In northern states, veterinarians recommend that horses be vaccinated in the spring before mosquito populations spike. In the South, boosters may need to be given more often. Reducing mosquito populations is another key to preventing Triple E.