Outbreak of Swine Malformations Associated With the Wild Black Cherry,<i>Prunus serotina</i>

Abstract

An outbreak of congenital malformations in swine occurred in Warren County, Missouri, during the late spring and summer of 1968. Sows which farrowed malformed offspring were bred and spent their gestation cycle in one pasture. Sows in an adjacent pasture bred by the same boar during the same period, farrowed only normal offspring. Field observation and epidemiologic studies indicate that the cause of the malformations was environmental in nature rather than hereditary. A comparison of the critical time period of exposure and environmental factors suggest an association between the malformations and consumption of wild black cherries (Prunus serotina) by the pregnant sows. Other environmental factors which might have contributed to the cause of the outbreak are discussed.