Foals are born without the protection necessary to fight off the infectious diseases that they will be exposed to early in life. The foal is primarily dependent on the protection it receives from the mare’s colostrum (first milk) consumed within the first 24 hours of life. Secondary protection will depend on the mare’s vaccination status.

A properly vaccinated pregnant mare that receive boosters 30 days prior to foaling will have a higher level of protection available for her foal than that of a non-vaccinated mare. The maternal antibodies protect foals that receive adequate colostrum from a vaccinated mare for a greater period of time. A condition called maternal antibody interference is another concern. Foal’s vaccinated during the time of maternal antibody protection will not respond properly to the vaccine. Studies suggest that proper foal vaccination protocol should begin with three primary vaccinations. This will allow an appropriate response to vaccinations and maximize disease protection.

The following is an example of an ideal vaccination schedule that has been recommended for foals from both vaccinated and non-vaccinated mares. As you will see, it can be very confusing. Consult with your veterinarian to determine an appropriate vaccination schedule, which is based on a multitude of factors including the use, environmental and risk exposure for the horse.