Pathomorphologic and differential diagnostics of diseases of avian digestive system

[Objective]The purpose of the research is to establish the most characteristic(pathognomonic)pathomorthological changes in avian diseases of various etiologies,occurring with a predominant lesion of the digestive system,classically and in the form of pathomorphosis.[Method]The corpses of chickens of egg crosses and broiler chickens of 1-42 days of age,replacement hen youngsters up to 120 days of age,laying hens of meat and egg crosses of 170-505 days of age admitted to the prosectorium of the Department of Pathological Anatomy and Histology of the EE VSAVM in 2014-2023.For histological examination,pieces of the esophagus,duodenum,jejunum,ileum,caecum and rectum,glandular and muscular stomachs,liver,pancreas,kidneys,myocardium,and brain were taken.Bacteriological and serological research was carried out in the veterinary production laboratories of poultry farms,and molecular biological-in the Vitebsk Regional Veterinary Laboratory.[Result]This paper presents the results of our own research on the pathomorphological diagnosis of avian diseases,accompanied by a predominant lesion of the digestive system:acute and chronic poisoning,A-hypovitaminosis,rotavirus infection,adenovirus hepatitis,viral(transmissible)proventriculitis,adenovirus erosive ventriculitis,parvovirus infection of broiler chickens,hepatitis E,necrotic(clostridial)enteritis,pullorosis,salmonellosis,enterococcosis,colibacillosis,eimeriosis,histomonosis.The results of studies of spontaneous material(corpses of birds,pieces of organs and tissues)were analyzed with subsequent laboratory confirmation of the preliminary diagnosis.The results obtained are formulated in the form of pathoanatomical and histological diagnoses.Attention is focused on pathognomonic(the most characteristic of a particular disease)pathological processes that are of decisive importance in the differential diagnosis of this group of diseases.Various variants of the pathomorphological course of diseases that proceed not only classically,but also in the form of pathomorphosis are considered.[Conclusion]Competent use of the methods of pathoanatomical and histological diagnosis of spontaneously occurring diseases of birds,accompanied by a predominant defeat of the digestive system,allows in an extremely short time to make the correct preliminary diagnosis,exclude complicating diseases,and timely conduct additional laboratory studies(biochemical,mycotoxicological,serological,PCR).