Establishment of a model of diarrhea due to damp heat in chickens
Chinese veterinary disease syndrome model is an effective tool to evaluate the efficacy and study the mechanism of action of veterinary medicine.In order to establish the chicken damp heat diarrhea syndrome model,SPF chicks were used as experimental animals,and the standard strain of Escherichia coli CVCC1558 and the self-isolated strain 09-29 were selected,respectively.Three different ways of chest intramuscular injection,oral gavage and cloacal perfusion were used,and different infection doses were selected to carry out the artificial infection test of Escherichia coli.Changes of necropsy,histopathology of duodenal mucosa and white blood cell count were detected.As a result,the experimental chickens showed different clinical manifestations and pathological changes with different infection methods.Compared with the blank control group,the oral gavage of 09-29 strain test group had no symptoms,and other groups of chickens showed different degrees of disease.In the two groups of oral gavage or cloacal gavage of E.coli CVCC1558 strain,the test chickens showed yellow green loose stool,increased body temperature,necropsy showed typical catarrhal or hemorrhagic enteritis changes,no pericarditis,perihepatic inflammation,balloon inflammation lesions,increased white blood cell count,duodenum villus epithelial cells fell off,and no sick chickens died.Syndrome differentiation analysis was carried out from the etiology,symptoms,pathogenesis and other aspects,it was completely consistent with the characteristics of damp heat diarrhea in Chinese veterinary medicine.In the three groups infected by intramuscular injection,although the experimental chickens also showed damp heat diarrhea,such as yellow loose stool and enteritis,the sick chickens were more likely to be extremely depressed,with systemic sepsis,such as pericarditis,perihepatic inflammation,and gasbag inflammation.The mortality rate was high,and the whole body symptoms were obvious.The fever had entered the blood camp,which was not consistent with the characteristics of simple damp heat diarrhea.The test showed that SPF chicks were given 3 mL of E.coli CVCC1558 strain orally or 3 mL of E.coli CVCC1558 strain in the cloaca,and the chicken model of damp heat diarrhea syndrome could be successfully established.The disease syndrome model established by this method fully conforms to the etiology,location,pathogenesis and syndrome characteristics of damp heat diarrhea syndrome in Chinese veterinary medicine.The clinical symptoms are obvious,the characteristics of necropsy are typical,the duration of disease is long,the model is stable,and the reproducibility is good.It is suitable for the prevention and treatment of damp heat diarrhea syndrome in chicken in Chinese veterinary medicine,and lays a foundation for the efficacy evaluation of prevention and treatment drugs.
damp heat and diuresisdisease syndrome modelchickenE.coli
国家科技期刊平台
NSTL
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