According to recent research published by the UC Davis School of Veterinary Medicine, the current recommendations for the primary rabies vaccine “are likely ineffective in foals” whose mothers are vaccinated against the disease.

The research indicates that the maternal antibodies in colostrum from mares vaccinated against rabies are transferred effectively to their foals and provide sufficient immunity against the disease.

“Vaccination of these foals should be delayed until six months of age or older, and the primary series should include two doses of vaccine administered one month apart.

“Current recommendations for [the primary] rabies vaccination that call for administration of one dose at three months of age or older, followed by a second dose at one year of age ... appear to be appropriate for foals from nonvaccinated mares.”