Abstract:In August 2022,50-day-old chickens in a certain chicken farm successively showed symptoms of weight lose and death,the mortality rate was about 0.2% per day,and the morbidity rate was about 10% per day until 110-day-old.Pathological dissection,PCR,RT-PCR,and qPCR detection,histopathological diagnosis,and bacterial isolation and identification were used to diagnose the diseased chicken,the results of PCR and RT-PCR were negative for ALV,MDV,REV and HEV,and positive for Escherichia coli.Pathological examination revealed nodules with size ranging from soybean seeds to quail eggs in the mesentery,kidneys,liver,lungs,and other parts of the diseased chickens,the histopathological findings showed characteristic granulomatous nodules in each tissue.By comparing pathological changes with avian tuberculosis,avian Marek's disease and avian lymphocytic leukemia,the aim is to provide materials for clinical diagnosis and differential diagnosis of diseases.
