Vaccine Strategies for Your Horse

Ted Johnson, D.V.M.

When choosing a vaccine strategy for your horse it is important to look at many issues, including his/her age, health condition, living environment, and activity level. Based on these factors, you and your veterinarian can determine a plan that will best protect against the various diseases to which your horse may be exposed.

All horses should receive a rabies and tetanus vaccine. For horses living alone or in a small group that never travels anywhere, these alone may be enough. The recent arrival of a vaccine for West Nile Virus for horses may be one to consider, although little is known yet as to how effective this vaccine is at preventing disease.

The young and older horses are more susceptible to various diseases, since their immune systems are weaker. Rhinopneumonitis (equine herpes) vaccine is generally reserved for pregnant mares or high risk horses. If there is concern about rhinopnemonitis, horses should be vaccinated every 3 months. It is wise to consult with your veterinarian about a vaccine protocol for pregnant mares and newborn foals before you plan a pregnancy. This preparation may spare the heartache of diseased or lost foals.

Geographic location and travel plans play a significant role in determining which vaccines to administer. For horses living in southern Vermont, your veterinarian may recommend vaccinating all horses for Eastern encephalitis. Even though this disease has been rarely reported, horses that travel to the southeastern U.S. should be vaccinated every 6 months. The Middle Atlantic States (Virginia and Maryland, for example) are areas where Potomac Horse Fever is prevalent. However, there is concern this disease is making its way north. Horses traveling to those areas or the show circuit should receive this vaccine twice a year. For horses that are competing or are exposed to horses moving in and out of show barns or auction houses, veterinarians may recommend the intranasal influenza and Strangles vaccines. Given in the nose, these vaccines produce local protective immunity, offering an excellent, rapid first line of defense. The flu vaccine is given every 6 months and the strangles vaccine is given annually.

A disease that is becoming more prevalent is Equine Protozoal Myelitis. This neurological disease is caused by an organism carried by opossums. With temperatures getting warmer in Vermont, more opossums are moving north. If horses in Vermont begin to develop signs of this disease, it may be necessary to consider using the newly developed vaccine against EPM.

Vaccine strategies are tailored to give your horse the best possible protection from disease. With proper prevention, your horse can remain a wonderful and healthy companion for many years.

Dr. Johnson is a member of the Vermont Veterinary Medical Association. For more information, visit www.vtvets.org.