HELENA, Mont. (AP) — Montana officials say two horses have tested positive for West Nile virus.

The state Department of Livestock said Wednesday the horses in Carbon and Powder River counties are the first cases reported in Montana since 2009. There were 14 cases that year.

State veterinarian Marty Zaluski says horse owners should consider vaccinating their animals.

Most horses recover from West Nile virus, though about a third of those infected die. The Department of Livestock says there is no specific treatment for the virus in equines.

Symptoms include loss of appetite, weakness, loss of coordination, muzzle twitching, impaired vision, convulsions and the inability to swallow, among others.