Equine influenza virus (EIV) is one of the leading respiratory diseases in the United States and, in recent years, the number of infected horses has been on the rise.

Since 2008, Merck Animal Health has collected more than 4,700 samples from horses presenting with signs of acute infectious upper respiratory disease and/or acute neurologic disease as part of an ongoing research program. The two leading diagnoses, based on samples submitted from horses of all disciplines and ages across the United States, have been equine herpesvirus-4 and EIV.

In an effort to protect horses against these two prevalent respiratory diseases, the United States Equestrian Federation (USEF) will implement a rule effective Dec. 1, 2015, mandating that all horses be current (within six months) on their EIV and equine herpesvirus vaccines prior to entering a USEF show.

A Step in the Right Direction

Kent Allen, DVM, volunteer chair for the USEF veterinary committee and drug and medications committee, believes the rule change will benefit both horses and show competitors.

“This rule change and uniformity of rules is going to help us not only better protect our horses against infectious upper respiratory diseases, but it also will improve the welfare of these show horses,” Allen said. “It is important for every owner, as well as the entire USEF organization to ensure that each horse is adequately protected through appropriate vaccination.”

Allen said the new rule will be straight-forward and easy for USEF competitors to implement.

“The bottom line is your horse must be current on their equine inf