Before I can answer this question I must have information about you and your horse.
- How old is your horse?
- How healthy is your horse?
- What diseases are present in your area?
- Where and how is your horse stabled?
- What activities do you and your horse participate in?
- How fearful are you that your horse will get sick or die if you do not vaccinate?
- Are you willing to change your management, if necessary, to prevent disease and support your horse’s immune system?
After these questions are answered I can recommend a vaccination protocol, but it is important for the horse owner to be educated about common equine diseases in order to participate in the final decision.
I recommend vaccinating healthy horses for this disease as it can be fatal. Equine encephalitis comes in three forms; Eastern, Western and Venezuelan. All three are combined with tetanus toxoid in one vaccine. This is commonly referred to as a VEW-T or 4-way vaccine. Equine encephalitis is a viral disease transmitted to the horse by mosquitoes which pick up the virus from an intermediate hosts, such as birds, small rodents and reptiles. This means your horse does not get this infection from or give it other horses, so even a backyard horse that never travels is at risk. To my knowledge, no research has been done to determine length of immunity, but vaccine manufacturers suggest annual vaccination. Until further information is available, I would suggest initial vaccination at 5 and 6 months of age followed by a booster every 3 years. If an outbreak is occurring, the booster can be given sooner. I would not vaccinate any horse over 15 years of age unless there is an outbreak.
This disease can also cause death if it is not treated early and aggressively. Tetanus is caused by the bacteria, clostridium teteni, which generally infects the horse through contamination of a wound. Vaccine manufacturers recommend annual vaccination, but horses have been known to have protection for up to 10 years from their last vaccination. I would suggest the same schedule as encephalitis with a booster given if horse sustains an injury and has not been vaccinated within the last 1 year.
This is not a vaccine, but an antitoxin against the tetanus neurotoxin. It should be given along with tetanus toxoid to an injured horse with unknown vaccination history. Tetanus prophalaxis should also be considered for such situations as foaling and surgery.
Horses can get rabies and it is fatal. To my knowledge there are no documented cases of a horse transmitting rabies to a person. To contract rabies, the horse must be bitten by a rabid animal. Wild animals such as skunks, fox, raccoons or bats are the usual sources of infection. Vaccine manufacturers recommend annual vaccination for horses, although the same vaccine is known to provide protection to dogs and cats for at least three years. There have been cases of rabies in vaccinated horses. I do not routinely advise vaccinating for this disease, but if you are concerned and choose to vaccinate, the manufacturer’s directions should be followed.
This is a respiratory disease caused by a virus. Symptoms include coughing, fever, loss of appetite and muscle soreness. It is rarely fatal. Uncomplicated cases recover in 1 to 3 weeks. It is acquired from other infected horses. The best treatment is rest and TLC. Immunity from vaccination is of very short duration, often less than 2 months. It is my opinion that vaccination causes more harm than good, and horses will become less susceptible as they mature. A healthy immune system is the best defense. In a study with racehorses, there was no difference in infection rates in vaccinated verses unvaccinated controls when the horses continued to work. In the same study, vaccinated horses that were taken out of hard training during the outbreak had lower infection rates. Unfortunately, this study did not include unvaccinated horses that were rested. I suspect they would have done just as well.