Equine vaccination protocols depend on several factors: geographic region, use, age, risk of exposure, environment and disease incidence.
Common horse vaccines are: Eastern Equine Encephalomyelitis, Western Equine Encephalomyelitis, Tetanus toxoid, Influenza, Rhinopneumonitis and West Nile Virus vaccines. Depending on the previously mentioned scenarios, horses may also receive Rabies, Strangles, Potomac Horse Fever, Equine Protozoal Myelitis, Botulism toxoid or Venezuelan Equine Encephalomyelitis vaccines.
Your local equine veterinarian is the best person to advise you regarding your horse’s vaccine protocol. He or she will be knowledgeable about the potential for disease exposure in your area and maintains the veterinary - client - patient relationship with you and your horse. Equine vaccine protocols change constantly and your veterinarian can provide you with updated recommendations.
Frequency and timing of equine vaccine boosters also depend on the vaccine protocol factors. The necessary vaccines will be recommended at least annually, but some may be needed more often.
Horses with a known vaccination history receive boosters. A horse with an unknown vaccination history or one who has not been vaccinated, will usually need an initial vaccination and at least one booster three to six weeks later. The boosters are necessary for the horse's body to build immunity against each disease; otherwise, the initial vaccine will protect the horse for a limited amount of time. Often the vaccines are recommended to be given in the early spring because more horses travel to events at that time of year. In addition, several of these diseases are spread by mosquitoes.
Vaccine labels advise the route and timing of administration but should not replace your veterinarian's recommendations.
Most equine vaccines are administered via the intramuscular route, but several are labeled for intranasal administration.
The intramuscular injections are commonly given in one of three muscle groups: the group of neck muscles just in front of the shoulder (A), the pectoral muscles (B), or low in the semitendinosus and semimembranosus muscles (C).
Vaccines are commonly administered in the neck muscles forming a triangular pattern in front of the horse's shoulder. The triangle boundaries are: the spine below, the nuchal ligament above, and the shoulder behind the triangle. Once the horse is properly restrained, insert the needle – syringe combination deep into the described muscle site, pull back on the syringe plunger to ensure a blood vessel has not been punctured then push the plunger completely into the syringe depositing the vaccine contents into the horse's muscle and withdraw the needle.
It is best to request your veterinarian demonstrate administration of intramuscular vaccines.
Your horse's history of possible vaccine reactions and your veterinarian’s preference site for administration will dictate the locations these vaccines should be administered. Vaccine reactions can occur, thus extreme caution should be used any time a horse is vaccinated.