Ileitis The No.1 health problem facing grow/finish pigs Ileitis, a gastrointestinal disease, is a common and costly problem. According to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, it is the No.1 health problem in growing pigs, as evidenced by both clinical and subclinical forms. The disease is also known as porcine proliferative enteropathy and is caused by the bacterium Lawsonia intracellularis. There are three forms of the disease – acute, chronic and subclinical. Nearly 42 percent of grow/finish operations reported clinical ileitis and nearly 94 percent of herds with no clinical signs were found to have subclinical ileitis.1,2Ileitis is known to cause thickening of the small intestine wall. Intestinal lesions can also form, affecting pigs’ growth and development. 1. USDA. 2007. Swine 2006, Part II: Reference of Swine Health and Health Management Practices in the United States, 2006. USDA:APHIS:VS, CEAH. Fort Collins, CO. #N479.12072. Armbruster GA, Deen J, Gebhart CJ, Pelger GA, Keffaber KK, Parks CW. Review of Lawsonia intracellularis seroprevalence screening in the United States, June 2003 to July 2006, in Proceedings. 38th Annu Meet Amer Assoc Swine Vet, 2007.