When Should Foals Be Vaccinated?
Vaccinating your foal helps it avoid potentially life-changing or life-threatening illnesses. Not sure when to vaccinate your foal? Take a look at the veterinarian-recommended vaccination schedule.
When Is the Right Time to Vaccinate Your Foal?
Foals can be vaccinated as early as three or four months, according to guidelines from the American Association of Equine Practitioners (AAEP). Vaccine timing may vary slightly, depending on the mare's vaccination history. Vaccinated mares pass on temporary immunity to foals through colostrum, the first milk the mare produces. The antibodies in colostrum offer some protection against disease during your foal's first few months, although immunity gradually decreases.
The AAEP divides vaccinations into core and risk-based categories. Core vaccines are recommended for all horses, while risk-based vaccinations may only be needed if a disease is widespread in your area or your horse is frequently in contact with horses from other parts of the country at shows or events.
Core vaccines protect your foal from:
- Rabies. Rabies is a viral disease transmitted through saliva or contact with the mucous membranes of an infected animal. Bats, skunks, raccoons, and foxes are the most common carriers of rabies. Unfortunately, an unvaccinated foal could encounter or be bitten by one of these animals during turnout or while in the barn. Rabies causes fever, colic, lameness, blindness, aggression, paralysis, and convulsions and is nearly 100% fatal.
- Rabies Vaccine Timeline. Foals born to vaccinated mares receive two doses of the rabies vaccine. The first dose is given at 4 to 6 months, and the second four to six weeks later. Foals born to unvaccinated mares receive one dose at 4 to 6 months. Annual rabies vaccinations are recommended after the initial doses.
- Tetanus. Tetanus kills up to 80% of infected horses, according to Merck Animal Health. The bacterium that causes tetanus is found in soil and manure and can enter your foal's body through a tiny cut or wound. Symptoms of tetanus include muscle spasms, leg stiffness, sweating, light sensitivity and the inability to open the mouth.
- Tetanus Vaccine Timeline. If the mare was vaccinated before giving birth, your foal will receive tetanus vaccinations at 4 to 6 months, four to six weeks after the first dose, and at 10 to 12 months. Foals born to unvaccinated mares receive initial tetanus vaccinations at 3 to 4 months, a second vaccination at four to six weeks, and a third vaccination at 10 to 12 months. Annual tetanus vaccinations are recommended.
- West Nile Virus. Horses infected with the West Nile Virus catch the disease after being bitten by mosquitoes that carry the virus. The virus has sickened more than 27,000 horses since 1999 and killed 30 to 40% of affected horses, according to the Equine Disease Communication Center. West Nile Virus may cause fever, drowsiness, muscle tremors, drooping lips and head, difficulty swallowing, circling, teeth grinding, coordination problems, facial or limb paralysis, lameness, and colic.
- West Nile Virus Vaccine Timeline. Foals of vaccinated and unvaccinated mares follow the same timeline for the West Nile Virus vaccination. The three-does vaccine is given at 4 to 6 months, four to six weeks after the first dose, and at 10 to 12 months. After receiving these doses, your horse will receive an annual vaccination for the West Nile Virus.
- Eastern/Western Equine Encephalomyelitis. Mosquitoes also spread Eastern (EEE) and Western Equine Encephalomyelitis (WEE), diseases that inflame the brain and spinal cord. Symptoms can include blindness, fever, coordination problems, and convulsions. Both diseases can kill horses, although EEE has a higher death rate than WEE.
- EEE/WEE Vaccine Timeline. The AAEP recommends giving the EEE/WEE vaccine for foals born to vaccinated and unvaccinated mares at 4 to 6 months with a second dose four to six weeks later. The third dose is given at 10 to 12 months. Annual EEE/WEE vaccinations will continue to protect your horse's health.
Your veterinarian may also recommend one or more risk-based vaccines, depending on your location and the prevalence of diseases in your area. Risk-based vaccines include anthrax, botulism, equine herpes virus, equine viral arteritis, equine influenza, leptospirosis, Potomac horse fever, snake bite, and strangles.
Vaccinations offer a simple way to protect your foal's health. Contact our office if you have questions about the immunization schedule or would like to make an appointment with the equine veterinarian.
Sources:
American Association of Equine Practitioners: Vaccinations for Foals
https://aaep.org/wp-content/uploads/2024/02/Foal_Vaccine_Chart_2023_SUB.pdf
Merck Animal Health: Foal Vaccinations
Equine Disease Communication Center: West Nile Virus
https://www.equinediseasecc.org/west-nile-virus
Equus: What You Need to Know About Eastern and Western Encephalomyelitis, 4/27/2022