Study Reveals Equine Influenza On The Rise

shotsWith studies showing the equine influenza virus is on the rise, the USEF is implementing a new rule regarding vaccination.Equine influenza virus (EIV) is one of the leading respiratory diseases in the United States and the number of horses infected 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 U.S., 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 be implementing a rule effective Dec. 1, mandating that all horses be current (within six months) on their EIV and equine herpesvirus (EHV) vaccines prior to entering a USEF show.

Kent Allen, DVM, volunteer chair for the USEF veterinary committee, as well as the drug and medications committees, said the rule change is going to be better for 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.”

According to Allen, the new rule will be straightforward and easy for USEF competitors to implement.

“The bottom line is your horse must be current on their equine influenza and equine herpesvirus vaccines by Dec. 1, 2015. If you maintain this vaccination schedule and obtain appropriate documentation, you will not only comply with the rule, but you also will ensure your horse is adequately protected against these highly contagious respiratory diseases.”

Even if you are not competing in USEF shows, EIV should still be a top-of-mind disease concern for all horse owners.

“This highly contagious virus can infect an entire barn of horses in less than 48 hours and it can take weeks to months for each infected horse to completely recover,” said D. Craig Barnett, DVM, Merck Animal Health director of equine veterinary technical services. “Owners and veterinarians alike need to make sure horses at risk for EIV are adequately protected through appropriate vaccination.”

Influenza is one of the most common and contagious equine respiratory diseases and can lead to significant time away from the saddle. If your horse travels, is in training, shows, races, is young or old, and/or comes in contact with other horses that meet the mentioned criteria, then it is at risk for contracting EIV.

“Owners need to be concerned about infectious upper respiratory diseases, especially the most prevalent like EHV-4 and EIV,” Barnett said. “Although they are not typically fatal, they can require significant recovery time and are certainly uncomfortable for the horse.”