Haemorrhagic enteritis of turkeys

出血性肠炎(HE)是幼龄火鸡的一种急性病毒性疾病,特征是突然发病,血便,死亡率不定,通常为高死亡率,还可以引起免疫抑制.血液从泄殖腔流出(图1),可在粪便中见到新鲜血液或黑粪症(图2).     

火鸡出血性肠炎

出血性肠炎(HE)是幼龄火鸡的一种急性病毒性疾病,特征是突然发病,血便,死亡率不定,通常为高死亡率,还可以引起免疫抑制。血液从泄殖腔流出(图1),可在粪便中见到新鲜血液或黑粪症(图2)。     

Bovine rotavirus in turkeys with enteritis

Rotaviruses are the main agents responsible for diarrhea in different animal species and for infantile gastroenteritis. These viruses have been isolated from various avian species and have often been associated with poult enteritis and mortality syndrome. Nevertheless, the knowledge of rotavirus infection in turkeys is scarce. Six group A rotavirus strains obtained from pooled enteric contents of diarrheic turkeys were isolated in MA-104 cell culture and typed as G(6)P(1), a typical bovine rotavirus genotype. Additionally, the electropherotypes showed a migration pattern identical to the Nebraska calf diarrhea virus, and the complete NSP4 gene phylogeny showed that all six strains segregated in the genotype E2. Taken together, these results point toward a cattle-to-turkey rotavirus transmission. As a conclusion, bovine-origin rotavirus can be found in turkeys, and this transmission route must now be considered for the improvement of the health status in turkey farms.     

Necrotic enteritis in cage-reared commercial layer pullets

Necropsy of five 12-week-old pullets from a flock of 99,300 suffering from an increased mortality rate revealed enlarged, gas-filled intestines, the mucosal surfaces of which had the "dirty turkish towel" appearance typical of necrotic enteritis. Although the pullets had been raised entirely in cages, intestinal scrapings revealed the presence of Eimeria maxima. Histopathological findings were compatible with necrotic enteritis. Clostridium perfringens was isolated by anaerobic culture from the intestines. Mortality returned to normal after bacitracin and amprolium were added to the feed.     

Focal hepatic necrosis in turkeys with hemorrhagic enteritis.

Disseminated acute focal hepatic coagulation necrosis was present in 9 turkeys submitted from 5 outbreaks of hemorrhagic enteritis. The lesion was unaccompanied by inflammatory cell infiltrate, biliary hyperplasia, or pancreatic necrosis, all of which tentatively distinguish this lesion from that of turkey viral hepatitis. No inclusion bodies were found.     

Pathology of spontaneous hemorrhagic enteritis of turkeys.

Thirteen turkeys naturally affected with hemorrhagic enteritis were studied pathologically. The main gross lesions were splenomegaly and hemorrhagic contents in the gut. The main histological lesions were intranuclear inclusion bodies in largemononuclear cells in many visceral organs and in reticular cells around the sheathed arteries of the spleens and varying degrees of lymphocytic hyperplasia in most tissues. The inclusions were frequently present in areas of the lymphocytic hyperplasia. The large mononuclear cells with the inclusions frequently showed a degenerative change.     

Necrotic enteritis in broiler chickens. III. Reproduction of the disease.

Lesions typical of necrotic enteritis could be produced experimentally in from 11-26% of broiler chickens consuming feed containing approximately 10(7) Clostridium perfringens per gram. Highest mortality was produced using isolates from field cases of necrotic enteritis which were reisolated from experimental cases in the laboratory. Penicillin in the drinking water at 100,000 I.U./litre completely prevented mortality whereas chloramphenicol at 110 mg/litre delayed the onset and reduced the number of deaths compared to controls.     

Necrotic enteritis: Applications for the poultry industry

Considering market demands concerning the decreased use of growth promoters and anticoccidial drugs in feed formulations, the poultry industry has been trying to reduce or eliminate the inclusion of subtherapeutic doses of antimicrobials into feed. Formulating diets not only to meet birds’ nutrient requirements for growth but also for gastrointestinal health parameters is increasingly important. Maintenance and enhancement of intestinal integrity is essential for bird performance when antimicrobials are not included in feed, as commercial poultry face numerous enteric pathogen challenges. Necrotic enteritis has reemerged as an important disease of poultry in recent years. The reduction in the use of antimicrobials in poultry feeds has been attributed as one of the main contributing factors for the increasing incidence of necrotic enteritis (NE) in commercial poultry. Mortality due to NE is extremely high (1% daily mortality), which results in great economic losses. Economic losses due to NE are not only associated with high mortality, but also associated with decreases in bird performance and FE, particularly in subclinical cases of NE. Birds that survive NE outbreaks usually have a reduced ability to digest and absorb nutrients due to extensive damage to the mucosal lining, which ultimately results in reduced profitability.     

Colibacillosis of turkeys exacerbated by hemorrhagic enteritis virus. Laboratory studies

Lesions typical of colibacillosis disease were reproduced in laboratory experiments. Mortality resulting from experimentally produced colibacillosis was significantly increased when Escherichia coli O1:K1 was presented to poults that had been orally inoculated with hemorrhagic enteritis virus (HEV) 1 week earlier. These and previous data suggest that HEV infection can exacerbate colibacillosis of older poults. HEV infection apparently damages the poults' defense system enough to account for the observed increase in susceptibility to E. coli.