Vaccines and Vaccination Overview for Horses
  by Robert N. Oglesby DVM

Currently there are equine vaccines available for:

• Tetanus : injection of modified toxin (toxoid)
• Eastern, Western, Venezuelan Viral Encephalomyelitis : injection of killed virus
• West Nile Viral Encephalomyelitis : killed virus (Fort Dodge) / modified live canarypox vectored (Merial)
• Influenza, many different strains : injection / intranasal
• Herpesvirus-1 : abortion, respiratory, and neurological disease
• Herpesvirus-4 : respiratory disease and abortion
• Strangles : injection of killed bacterin / intranasal vaccine (Fort Dodge)
• Rabies : injection of killed virus
• Potomac Horse Fever : killed rickettsia
• Equine protozoal Myelitis (EPM): killed protozoan
• Botulism : injection of modified toxin (toxoid)
• Equine Viral Arteritis
• Anthrax
• Endotoxemia
• Rotavirus

With all the vaccines available there is probably no harder decision that a horse owner makes than what to vaccinate for and how often. Just a few of the problems with general recommendations is that:

• The incidence of these diseases differs in different parts of the world, different countries, and even smaller geographical areas.
• The efficacy and safety of these vaccines vary remarkably.
• Even your goals effect which vaccines you should use.

Often incomplete information is available on vaccine efficacy and safety. On top of all this, the equine news media makes each disease outbreak sound like impending doom for your horse and rarely question the safety, efficacy, or necessity of vaccination issues.

The bottom line is you only will want to vaccinate for those problems that occur locally, for which your horse is at risk for, and for which there are safe, efficacious vaccines. Even when these criterion are met there still may be some milder diseases for which vaccination is not prudent. The risk of many diseases can be greatly reduced by understanding how your horse contracts the disease and instituting preventive measures. This article discusses in detail the decision to vaccinate, how these vaccines work and don't work, vaccine safety and reactions. The vaccines themselves are listed and briefly discussed then linked to detailed articles on the disease and vaccines available. Links are also provided to specific vaccine schedules for different circumstances and articles on how to give vaccines.