Amesbury Animal Hospital

277 Elm Street
Amesbury, MA 01913



Vaccinations, along with regular examinations by your veterinarian, are one of the best and most effective ways to protect your horse's health. The vaccines and vaccine protocols listed below are tailored to our practice and geographic location and follow the guidelines of the AAEP (American Association of Equine Practitioners). Depending on your horse's age, heath status, barn or travel plans, we may tailor a more specific vaccination protocol to your needs. After a thorough physical examination, your veterinarian can discuss which vaccines are recommended for your horse.

Vaccines are preparations of killed microorganisms, living weakened microorganisms, or even DNA fragments of microorganisms that are introduced into the body to produce immunity to a specific disease by causing the formation of antibodies. Because vaccines are designed to stimulate an immune response, it is not unusual for a horse to experience mild and transient side effects (just like children). Local muscle soreness or swelling, low grade fever (<102), decreased appetite or fatigue are all common side effects, usually experienced within the first 24 hours following vaccination. If any of these mild side effects persist for longer than 24 hours, contact your veterinarian.

More serious side effects are rare, but can occur. You should contact your veterinarian immediately if you notice any hives, difficulty breathing, colic or even collapse (anaphylaxis) after vaccination.

Vaccines are very delicate compounds, which if handled or administered incorrectly will be ineffective or neutralized. Your veterinarian understands your horse's lifestyle and disease risks as well as how to appropriately handle and administer the vaccines for your horse's situation. Vaccines are administered initially in series 3-4 weeks apart and then annually or semiannually. Occasionally, a vaccine may not be as effective for a variety of reasons including a compromised immune system, exposure to disease prior to vaccination, overwhelming challenge by infectious agent, or improper handling or storage of the vaccine.

There are several ways you can make your horse more comfortable after vaccination. Following vaccination, walk or allow free-choice exercise for 20-30 minutes to increase blood flow to muscles. This can help reduce muscle stiffness. Minimize strenuous activity for 2-3 days to allow your horse's immune system to generate a good response to the vaccines as well as allow any "normal" post-vaccination side effects to diminish. Occasionally, non-steroidal anti-inflammatory medications (such as bute or banamine) may be needed to keep your horse more comfortable. Contact your veterinarian prior to administering any medications.

In our practice, we recommend the following vaccines. We consider the first four listed as the core vaccines, recommended for all horses. The remaining vaccines are administered based on certain risks or exposure:

Eastern & Western Equine Encephalomyelitis: Encephalomyelitis is caused by a virus, which is transmitted by mosquitos. The virus causes inflammation of the brain and spinal cord, leading to a variety of neurological symptoms including behavioral changes, loss of appetite, fever, dementia, head pressing, circling and often blindness. EEE is fatal in 75-90% of cases, WEE is fatal in 20-40% of cases. Treatment is generally supportive and there may be long term abnormalities in horses that survive. The vaccine is very effective against the disease. After the intial series, we recommend administering the vaccine yearly and in some cases, twice a year depending on your location in an endemic area or travel plans.

Tetanus Toxoid: Tetanus is a disease caused by a specific toxin of a bacillus (Clostridium tetani) which usually enters the body through wounds. It is characterized by spasmodic contractions and rigidity of some or all of the voluntary muscles (especially of the jaw, face and neck). Affected horses will walk with a stiff gait progressing to rigid paralysis and possibly convulsions. Death can occur due to paralysis of the muscles used for breathing. The bacteria is found in horse manure and the environment. The vaccine is very effective and administered once yearly. The vaccine is boostered in case of laceration, surgery, or pentrating wounds.

Rabies is a viral disease that infects the nervous system of mammals. It is transmitted through contact with the saliva of infected animals. Signs of this disease are variable. It is 100% fatal and is transmissible to humans. The vaccine is given once yearly and is very effective.

West Nile Virus: West Nile virus is transmitted by mosquitos. The virus causes inflammation of the brain and spinal cord. Signs of this disease include low-grade fever, inappetance, lethargy, and neurological signs characterized by problems maintaining balance and strength. After the intial series, we recommend boostering this vaccine yearly before the start of mosquito season and in some cases, twice a year depending on your location within an endemic area or travel plans. Horses that travel south should be boostered 2 weeks before travelling.

Rhinopneumonitis: Rhinopneumonitis is a herpes virus which causes respiratory infections, abortions, and inflammation of the spinal cord. The vaccine is not 100% effective and the protection only lasts 10-12 weeks.  Pregnant mares should be vaccinated at 3.5, 7 and 9 months from the breeding date. Horses that are travelling to shows, races, sales, etc. should be vaccinated every 3 months. Pleasure horses that do not travel should be vaccinated twice a year. The vaccine does not protect against the neurologic form of the disease.

Influenza: Influenza is a virus that causes high fever and respiratory infection. The vaccine is not 100% effective, and the protection lasts only 10-12 weeks. Horses travelling to shows, sales, racing events, etc. should be vaccinated every 3 months. Horses that do not travel should be vaccinated at least twice a year. This vaccine is often combined with the rhinopneumonitis vaccine.

Potomac Horse Fever(PHF): Potomac Horse Fever is caused by the parasite Ehrlichia risticii. Horses are infected through small land snails that carry the parasite. It is not contagious and occurs more commonly in wet areas. The disease can cause high fever, laminitis, and severe diarrhea. The vaccine is fairly effective and is administered once a year. It is administered 2-4 times yearly in problem areas.

Strangles: Strangles is a bacterial disease caused by Streptococcus equi. It is highly contagious and causes the following signs: high fever, abscessed lymph nodes, and respiratory infection. Horses may develop guttural pouch infections, sinus infections, purpura hemorrhagica, laryngeal paralysis, and bastard strangles. There is an intranasal vaccine which is more effective than the intramuscular vaccine. The vaccine is usually given once a year. In endemic barns (that have frequent outbreaks) or for horses that travel extensively, we may recommend twice yearly vaccination.