Equine viral arteritis at a veterinary teaching hospital

An outbreak of equine viral arteritis (EVA) occurred at a veterinary teaching hospital in the summer and autumn of 1984. Clinical signs were observed in 16 out of 61 hospitalized horses and included ventral, limb and preputial edema, mild conjunctivitis with lacrimation, pyrexia and increased respiratory and heart rates. Of 16 clinically affected horses, 13 were undergoing experimental abdominal surgery and/or were involved in digestion experiments; 9 of the 13 were > 20 years of age. The three other clinically affected horses were client animals. Thirteen client horses developed serologic titers to equine arteritis virus in the absence of clinical signs. The risk of infection was associated with close contact, involvement in the experimental studies being conducted and length of hospitalization. The disease was mild, limited in spread and successfully controlled by quarantine.