7Alderton M R, Borland R, Coloe P 3. Experimental reproduction of porcine proliferative enteritis[3].J Comp Aath, 1992,106:159-167.
8Joens L A, Nihbelink s, glock R D. Induction of gross and microscopie lesionsof procine proliferative enteritis by Lawsonia intracellaris[J].AJYR, 1997,58:1125-1131.
9McOrist S,.Lawson G H K, Rowland A C. et al. Early lesions of proliferative enteritis in pigs and hamsters [J].Vet Pathol, 1989,26:260-264.
10Knittel J, Kroll J, Mathes Met al. Efficacy of an avirulent Lawsonia intracellularis vaccine in swine[M]. Proc IPVS. 2000:16,24.
4Smith S H, McOrist S. Development of persistent intestinal infection and excretion of Lawsonia intracellularis by piglets [ J ].Research in Veterinary Science, 1997,62 ( 1 ) : 6-10.
5Winkelman N L, Dee S.Ileitis:an update [J].Compendium of Continuing Education of Practicing Veterinarians,1996,18:19-25.
6Huerta B, Arenas A, Carrasco L, et al. Comparison of diagnostic techniques for porcine proliferative enteropathy (Lawsonia intracellularis infection) [J]. J Comp Path,2003, 129:179-185.
7Biester H E, Schwarte L H. Intestinal adenoma in swine [J]. American Journal of Pathology,1931,7 : 175-185.
8Lawson G H K, McOrist S. The enigma of the proliferative enteropathies: a review [J].Journal of Comparative Pathology, 1993,108:41-46.
9Jacobson M, Gerth Lofstedt M, Holmgren N, et al. The prevalences of Brachyspira sp. and Lawsonia intracelhdaris in Swedish piglet producing herds and wild boar population [J ].J Vet Med B, 2005,52 : 386-391.
10McGurrin M K, Vengust M, Arroyo L G, et al. An outbreak of Lawsonia intracellularis infection in a standardbred herd in Ontario [J].Can Vet J,2008,48 : 927-930.