West Nile and Eastern Equine Encephalitis (Triple E) have both been found in Virginia. The state says you should be sure to vaccinate against the viruses.
The Triple E vaccine has been around for a while and is proven to work. But, the West Nile vaccine has only been around a year and it's still being tested.
"It does protect against the disease to our knowledge, " said Dr. Tom Burgess of Stonewall Veterinary Hospital. "But we don't know to what percentage of effectiveness it actually does for us."
Burgess says to fight against West Nile and Triple E, the best thing to do is to keep the mosquito population down.
He suggests putting fly repellent on your horses, putting them in a stable or barn at night and getting rid of any standing water close to your horses.