PECULIARITIES OF PATHOMORPHOLOGICAL DIAGNOSIS OF THE MOST COMMON RESPIRATORY INFECTIONS OF A PIG

Abstract

The active spread of respiratory infections in pig farms raises the issue of differential pathomorphological diagnosis of diseases related to a single syndrome of respiratory pathologies. Pathological autopsy and histopathological examinations of organs from 72 carcasses of pigs during the fattening period were performed. Pathological autopsy of pigs was performed by complete evisceration. Histologically examined 360 lung samples with regional lymph nodes. The presence of bacterial and viral infections was confirmed by bacteriological and PCR studies. The aim of the study is to establish the characteristic differential features at the macro- and micro-level in the lungs of domestic pigs for viral and bacterial pathogens. The main tasks of the work are to determine the morphofunctional features and dynamics of pathomorphological changes in the parenchyma and immune formations of the lungs in respiratory pathology. As a result of complex pathomorphological studies of the lungs in respiratory infections of pigs found that structural and functional changes in the body have different localization, stage and nature of the pathological process, which depend on the direct action of the etiological factor. Acute catarrhal bronchopneumonia is registered in respiratory mycoplasmosis (enzootic pneumonia), which in a prolonged course turns into chronic catarrhal or catarrhal-purulent pneumonia. Hemorrhagic necrotizing pneumonia is a manifestation of actinobacillary pleuropneumonia. Interstitial (diffuse proliferative) pneumonia develops with viral pathogens - circovirus infection and reproductive and respiratory syndrome of pigs (PRRS). Serous fibrinous and fibrinous pleurisy develop in hemophilic polyserositis and actinobacillary pleuropneumonia. Pathomorphological changes of the lungs in the reproductive and respiratory syndrome of pigs are polymorphic and are manifested by the gradual progressive development of the inflammatory process from congestive hyperemia, acute catarrh to diffuse interstitial pneumonia. Pathomorphological changes of the lungs in mycoplasmosis (enzootic pleuropneumonia) of pigs are polymorphic and are manifested by the gradual progressive development of the inflammatory process, which is localized in the cranial, middle and peripheral parts of the diaphragmatic particles and is characterized by acute catarrhal bronchopneumonia. In actinobacillary pleuropneumonia pathohistological studies revealed a pronounced stage of morphological changes in the lungs and regional lymph nodes in actinobacillary pleuropneumonia. Depending on the form of the disease, serous-hemorrhagic exudation is exacerbated by fibrinogen exudation and increased migration of lymphocytes and mononuclear cells. In subacute and chronic forms of the disease, necrotic phenomena prevail in combination with areas of serous-fibrinous inflammation. In the future, further studies of immunohistochemical analysis to establish the tropism of the pathogen and the study of markers of lymphoid cells.