A tobacco related epidemic of congenital limb deformities in swine

Abstract An epidemic of congenital limb deformities in swine is described. The epidemic occurred among 79 Duroc sows and gilts on a farm in Howard County, Missouri, during the period September 11, 1967, to March 3, 1968. The 79 females farrowed 782 pigs: 742 (95%) were born alive, 40 (5%) were born dead, and 59 (7.5%) were born with congenital abnormalities. The abnormal pigs were farrowed by 14 sows. These sows farrowed 149 pigs and 59 (40%) were abnormal. Tobacco stalks were placed in a swine lot and pasture between October 25, 1967, and December 7, 1967, and some of the sows were observed eating the stalks. On December 7, 1967, four sows had an illness which lasted 24–48 hours. The first 38 days of pregnancies in those sows with the affected progeny occurred during the time when the tobacco was available to them. Other animals not exposed to the tobacco stalks as a food source had no birth defects. The animals involved in the epidemic during prior and later reproductive periods had no abnormalities in their litters. The tobacco stalks, therefore, appeared to have some association with the epidemic. The tobacco stalks were tested for nitrate-nitrogen, pesticides, fungi, nicotine, and maleic hydrazide. The nitrate-nitrogen varied from 20 to 1390 ppm, and no significant amounts of aldrin, dieldrin, or pp′ -DDT were found. The fungi consistently isolated included a species of Penicillium identified as a variant of Penicillium cyclopium . Other species of fungi were isolated only sporadically, and no Aspergilli were found. Nicotine, other alkaloids or components of the tobacco stalks, appeared to be the most likely cause of the epidemic. The tobacco stalks eaten by the swine contained 1058 ppm of nicotine and 115 ppm of maleic hydrazide. The possible relationship of this epidemic of birth defects in swine associated with the ingestion of tobacco stalks to the increased fetal loss described among smoking mothers is discussed.