Preparing the Next Generation: Initial Vaccinations for Foal

With the foaling season in full swing, new foals are enjoying life at farms, ranches, and breeding facilities around the country. While most foals are protected from common equine diseases by maternal antibodies in the mare's colostrum (the mare's first milk that antibodies that help protect the foal's immune system) for the first few months of life, they need to start a course of vaccinations as soon as those maternal antibody levels begin to drop.

Only a veterinarian can provide guidance on when to vaccinate. Approximately four to six weeks prior to foaling, mares should be given a pre-foaling series of vaccinations to boost the antibody levels in the colostrum they produce.

Foals that receive and absorb a mare's colostrum within 24 hours of birth receive maternal antibodies that help protect them from most infectious diseases and should not be vaccinated until these maternal antibody levels decline. If vaccinated too early, colostral antibodies can block the foal's immune response.

"Antibodies in a mare's colostrum can block the foal's ability to mount an effective protective immunity, so owners and breeders need to coordinate initial vaccinations based on when those maternal antibodies drop off and when the mare was last vaccinated," said Tom Lenz, DVM, MS, senior director of equine veterinary services for Pfizer Animal Health. "Foals are most vulnerable at around three to four months old when maternal antibodies are decreasing and they have not yet been vaccinated."

Core vaccinations for foals include Eastern and Western encephalitis (EEE and WEE) viruses, West Nile virus, tetanus, and rabies. If they travel to horse shows, racetracks, or other locations where they might be exposed to other horses, foals should also receive vaccination against equine herpesvirus types 1 and 4 as well as equine influenza virus. For more information on appropriate foal vaccinations, contact your veterinarian.

"Developing a vaccination program with your veterinarian helps provide the best individualized protection based on the risks in a specific location," said Lenz. "Initial vaccinations for foals help develop protection from these common diseases, so it's important to cover the core vaccinations and any other diseases to which they may be exposed."

Pfizer Animal Health has a complete line of equine vaccines to help protect against common equine diseases, including WEST NILE-INNOVATOR and FLUVAC INNOVATOR. Other available combinations include protection against EEE and WEE. Contact your veterinarian for more information on available vaccines.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More