Equine viral arteritis (EVA) is caused by an RNA togavirus, and produces clinical signs of respiratory disease, vasculitis, and abortion. Horses with EVA infection present with fever, anorexia, and depression. The clinical signs of respiratory infection due to EVA are serous nasal discharge, cough, conjunctivitis, lacrimation, and palpebral and periorbital edema. Clinical signs of disease persist for 2–9 days. Treatment consists of supportive care (support bandages), and NSAID for fever and inflammation. Antimicrobial therapy is usually unnecessary. A carrier state occurs in most stallions following natural infection and is primarily responsible for persistence of the virus in the horse population. Vaccination (modified live virus) is targeted toward prevention of venereal spread of EVA in breeding animals, as opposed to prevention of respiratory disease. (see Equine Viral Arteritis.)

Last full review/revision March 2012 by Bonnie R. Rush, DVM, MS, DACVIM