Texas (NBC) — Concerns are mounting tonight over a growing number of cases of horse herpes in nine western states, including Texas.

The uncommon viral disease was reported in horses that participated in a national championship in Utah a few weeks ago.

The contagious disease is spread from horse to horse through nose contact, contaminated tack, equipment or clothing.

It attacks the animals' central nervous system and could lead to death if left untreated.

However, it is not contagious to humans.