Contact with farm animals in early life and juvenile inflammatory bowel disease: A case-control study

Objective. The aim of this study was to test the association between farm animal contact in infancy and the development of juvenile Crohn disease and ulcerative colitis. Methods. A case-control study was conducted in 13 children's hospitals by using a mailed questionnaire. Case subjects with Crohn disease or ulcerative colitis who were registered in these hospitals were eligible ( response rate: 90%). Children who underwent strabismus surgery at 11 of the 13 centers served as control subjects ( response rate: 85%). All children 6 to 18 years of age who were born in Germany without malformations were included ( 444 case subjects with Crohn disease, 304 case subjects with ulcerative colitis, and 1481 control subjects). Results. Regular contact with farm animals during the first year of life was associated inversely with Crohn disease and ulcerative colitis. In addition, regular contact with cats in infancy was linked inversely with case status. Allergic rhinitis was correlated significantly with Crohn disease but not with ulcerative colitis. Conclusion. Contact with farm environments in infancy might decrease the risk of juvenile Crohn disease and ulcerative colitis.