Rabies is one of those diseases you want to avoid at all costs–it's rapidly progressive, fatal, and can be transmitted from your horse (or any other infected animal) to you. While vaccines are available for horses, no data was published on their efficacy in the literature until December 2009.

At the 2009 American Association of Equine Practitioners (AAEP) Convention, held Dec. 6-10 in Las Vegas, Nev., a study on the efficacy of the EquiRab rabies vaccine was presented by Craig Barnett, DVM, equine technical services veterinarian at Intervet/Schering-Plough Animal Health.

"Rabies surveillance shows about 7,000 cases of rabies annually (in the United States), mostly in wildlife, but also 30-50 cases of equine rabies per year," Barnett said. "These numbers represent only a fraction of what's actually out there."

For this study, which was done as part of the registration requirements to license the vaccine, 26 horses were vaccinated with EquiRab (single 1-mL dose) and 11 served as unvaccinated controls. "All vaccinated horses developed high levels of rabies virus-neutralizing antibody that persisted for at least 12 months," Barnett reported. In addition, horses with the lowest antibody levels were challenged with injected rabies virus 14 months after vaccination. No vaccinated horses developed disease, but 80% of the unvaccinated controls did