Equine rhinopneumonitis (inactivated)

EHV-1 at 5, 7, and 9 months of gestation; EHV-1/EHV-4 4–6 weeks before due date

Tetanus (toxoid)

4–6 weeks before due date

Equine influenza

4–6 weeks before due date; if unvaccinated, initially administer two doses at 4–6 week intervals and then a third dose 4–6 weeks before due date

Eastern and Western equine encephalomyelitis

Usually administered to mares in late spring or early summer before onset of insect season; initially administer two doses at a 4–6 week interval; 4–6 weeks before due date

Rabies

4–6 weeks before due date

Botulism (toxoid)

Initially three doses at 4–6 week intervals, then annual booster 4–6 weeks before due date

West Nile virus

Initially two doses at a 4–6 week interval; 4–6 weeks before due date

Rotaviral diarrhea

8, 9, and 10 months of gestation

Equine viral arteritis (modified-live virus)

A negative titer should be documented by a USDA-approved laboratory before vaccination; pregnant mares should not be vaccinated; open mares should be vaccinated before breeding to a positive stallion that is shedding the virus; vaccinated horses must be isolated for 3 weeks after vaccination; annual boosters recommended; positive titers may cause problems if mare is to be exported or bred on certain farms. (Stallions should also be vaccinated 3 months before breeding.)

Equine monocytic ehrlichiosis (Potomac horse fever)

Initially administer two doses at a 3–4 month interval; 4–6 weeks before due date