Q.What vaccines should my horse have if I plan on showing this year? For example, I’m not sure if my horse should receive a strangles vaccine.

—Via e-mail

A.Vaccine selection is typically based on the risks and benefits for the individual horse. Ultimately, you’ll want to work with your veterinarian to determine your horse’s risk for various diseases, but here are a few things to consider in the meantime.

Core Vaccines

The American Veterinary Medical Association defines “core vaccines” as those “that protect from diseases that are endemic to a region, those with potential public health significance, required by law, virulent/highly infectious, and/or those posing a risk of severe disease. Core vaccines have clearly demonstrated efficacy and safety, and thus exhibit a high enough level of patient benefit and low enough level of risk to justify their use in the majority of patients.”

Based on this definition, the American Association of Equine Practitioners have identified the following as equine core vaccines:

• Eastern and Western equine encephalomyelitis;
• Rabies;
• Tetanus; and
• West Nile virus.

These vaccines have high efficacy and minimal side effects and protect against diseases endemic to the U.S.

Risk-Based Vaccines

Horses participating in events such as shows or sales are at a heightened risk for pathogens spread by contact (direct or indirect) with other horses. Most notably, this includes equine influenza and equine herpesvirus. Many show associations—including US Equestrian—and venues require proof of vaccination against these highly contagious pathogens within the past six months in order for a horse to be admitted to the facility or competition.

Consult your veterinarian about whether your horse would benefit from other risk-based vaccines, including the strangles vaccine you mentioned or those that protect against diseases such as botulism, Potomac horse fever, or leptospirosis. He or she can help you make the decision to vaccinate based on disease prevalence in your area, whether your horse is particularly at risk, and the efficacy and adverse effects associated with the vaccine in question.