title: Quantification of gut lesions in a subclinical necrotic enteritis model.
abstract: Currently Clostridium perfringens-induced necrotic enteritis is a major problem in broiler flocks. In the present study, broilers were inoculated with a combination of Eimeria maxima or overdose coccidial vaccine (one inoculation) with C. perfringens (repeated inoculations). Single C. perfringens, E. maxima or an overdose of live coccidial vaccine inoculations did not result in grossly visible necrotic gut lesions, while combined inoculation resulted in typical necrotic lesions at approximately 4 days after inoculations with C. perfringens in approximately one-half of the inoculated animals. Semi-quantitative histological lesion scoring was done to evaluate gut damage in gut sections of animals in which no gross necrotic lesions were detected. This included scoring of hyperaemia, haemorrhages, the amount of red blood cells and protein precipitate in the lumen, villus fusion and epithelial defects. The villus length and the villus length/crypt depth ratio were also analysed. This approach proved to be discriminative between single E. maxima infection, overdose of coccidial vaccine or C. perfringens inoculations and the non-inoculated control group, and between the double-inoculated and single-inoculated groups. In general, the highest histological scores for gut lesions were observed in the double-inoculated groups, but the single-inoculated groups had higher scores than the control group. It was concluded that oral inoculation of broilers with an overdose of live coccidial vaccine in combination with multiple oral C. perfringens inoculations is a suitable model for necrotic enteritis without inducing mortality of the animals. C. perfringens and Eimeria act synergistically in inducing grossly visible gut damage.
authors: Research Group Veterinary Public Health and Zoonoses, Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors: Ahmad R
authors: AR
authors: Gholamiandehkordi
authors: Leen
authors: L
authors: Timbermont
authors: Anouk
authors: A
authors: Lanckriet
authors: Wim
authors: W
authors: Van Den Broeck
authors: Karl
authors: K
authors: Pedersen
authors: Jeroen
authors: J
authors: Dewulf
authors: Frank
authors: F
authors: Pasmans
authors: Freddy
authors: F
authors: Haesebrouck
authors: Richard
authors: R
authors: Ducatelle
authors: Filip
authors: F
authors: Van Immerseel
mesh_terms: D000818:Animals; D002645:Chickens; D003015:Clostridium Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D003016:Clostridium perfringens; D004751:Enteritis / Q000473:pathology / Q000662:veterinary*; D005260:Female; D007422:Intestines / Q000473:pathology*; D008297:Male; D009336:Necrosis / Q000473:pathology / Q000662:veterinary*; D011201:Poultry Diseases / Q000382:microbiology / Q000473:pathology*