Cecal spirochetosis in commercial laying hens.

Cecal spirochetosis in chickens has been associated with enteric disease and reduced egg production in the United States and Europe. This report describes spirochete overgrowth of cecal mucosa in chickens from a flock of 100,000 commercial layers experiencing diarrhea and a 5% drop in egg production. Spirochetes were demonstrated in the ceca by darkfield and light microscopy. Apical surfaces of cecal enterocytes were covered by a dense layer of spirochetes aligned parallel to each other and perpendicular to the mucosal surface. Weakly beta-hemolytic, indole-negative spirochetes were isolated from the ceca on BJ media under anaerobic conditions at 42 C. Chicken cecal spirochetosis may represent an economically significant enteric disease of laying hens which has heretofore been infrequently recognized.