) Protects against strangles caused by Strep equi. Made with concentrated M-protein extract to provide good protection with a minimum amount of side effects. Dosage is three 1 ml doses given at 3 week intervals initially, with an annual booster thereafter. Foals less than 3 months should receive an additional dose at 6 months or at time of weaning. Consult with your veterinarian about the advisability of vaccinating for Strangles.