FIELD: veterinary medicine. SUBSTANCE: the method deals with injecting for sows a prophylactic preparation containing (weight%): formaldehyde 0.03-0.12, sodium chloride 0.9-0.95, distilled water - the rest. Moreover, the preparation suggested is injected at 4-6 ml/sow dosage twice or thrice at 7-10 d interval at the last injection of preparation 7-10 d before furrowing. To eliminate reinfecting in neonatal piglets or superinfecting in milking sows it is necessary to conduct additional treatment of piglets within 24-48 h after their birth. EFFECT: increased efficiency in preventing reproductive- respiratory syndrome in unsuccessful farms in piglets during neonatal and milking periods. 1 cl, 3 ex, 3 tbl
