Over the past year there has been considerable fear in the breeding industry–especially the Quarter Horse industry–about the spread of equine viral arteritis (EVA). Although the disease has been around for a long time, confirmed outbreaks of EVA are relatively infrequent.

The most recent series of outbreaks started with the shipment of equine arter itis virus (EAV)-infective semen from a breeding farm in New Mexico to numerous other states; it spread to Quarter Horses in 10 other states, the majority in the western United States. It was first detected on the index premises when groups of mares were found to have lost their pregnancies when routinely pregnancy-checked at 60 days. Semen from one of the stallions on that farm had been shipped to 18 states, establishing infection on premises in the majority of them. The economic threat from this virus and this disease primarily involves breeding stock. In nonbreeding horses, EVA will run its course in a short period of time, with no residual clinical or other effects for the recovered individual. However, intact males might become lifelong carriers and shedders of the virus.

Understanding the significance of this virus to your particular horse operation will enable you to take preventive measures to minimize its potential impact on your herd. Although EVA is currently a reportable disease in many states, it is not reportable at the national level, making it necessary for you to take the appropriate steps to protect your horses