The multistate equine herpesvirus outbreak in May 2011 illustrated the importance of infectious disease control in the equine community. At the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio, Texas, Jerry Black, DVM, summarized the outbreak in a group table topic discussion that he moderated with Josie Traub-Dargatz, DVM, MS, Dipl. ACVIM. Both are part of the faculty at Colorado State University, in Fort Collins.

He explained that horses had dispersed from an Ogden, Utah, cutting horse event just prior to recognition of the first confirmed cases. The veterinarian examining the initial two sick horses recognized how serious the situation was and reported the cases immediately to the Colorado state veterinarian. This communication was a critical factor in limiting the extent of viral spread.

Black explained that show officials made immediate decisions to cancel cutting horse shows in California, Nevada, and Oklahoma. Horses coming in from the Ogden Cutting Horse Championship were turned around before entering these show grounds, and future cutting horse shows were canceled for three weeks. Financial losses for the show organizers, traveling owners, and trainers were significant, he noted.

By the end of the first weekend, additional cases arose among some horses that had attended the Ogden event. Black reported that social media grossly exaggerated reports of the number of sick horses, noting, "There was a need for reliable industry sources of information to disseminate accurate facts rather than rumors." Calls to the American Horse Council, the American Association of Equine Practitioners (AAEP), and contact with the USDA Animal and Plant Health Inspection Service’s Veterinary Services (USDA:APHIS:VS) initiated surveillance and monitoring of the outbreak as well as accurate reporting