Pathological and pathohistological characteristics of African swine fever in the western region of Ukraine
Abstract
O. Shchebentovska*, O. Zaytsev, A. Tybinka, O. Lozhkina, M. Kupnevska and S. Lytvynenko
African swine fever is one of the most severe transboundary diseases, included in the list of dangerous animal diseases (TAD) identified by EMPRES (Emergency Prevention System for Transboundary Animals and Plant Pests and Diseases). This disease causes significant damage to the economy, trade, and food security of various countries and can quickly spread from one country to another, reaching the scale of epizooty. The ASF (African swine fever) virus is a pantropic one with a selective effect on lymphoid cells and vascular endothelium. After the virus enters the body through the blood and lymphatic vessels, it reproduces in sensitive cells. A cytopathic effect accompanies the process on leukocytes, macrophages, and endothelial cells. The article describes the clinical picture, pathological and histological changes in various organs of pigs during the acute progression of ASF. The following manifestations characterize the clinical manifestations of the disease: a temperature increase up to 42°C, skin cyanosis of the ears and abdomen, shortness of breath, arrhythmia, diarrhea with blood impurities, and partial paresis. Postmortem changes developed quite rapidly. The pathological autopsy revealed bloody discharge from natural openings, serous infiltrates in the subcutaneous and intermuscular connective tissue, splenomegaly, hemorrhagic lymphadenitis, multiple spot hemorrhages in the parenchyma of the kidneys and liver, serous edema of the gallbladder wall, pulmonary edema and hemorrhagic pneumonia, hemorrhage in the endocardium, and heart valves. Morphologically, diffuse karyorrhexis of lymphocytes, necrosis of lymphoid nodules, and diffuse lesion of blood vessel walls were found in the spleen of pigs. Alternative serous hemorrhagic lymphadenitis was detected in the lymph nodes. There was a massive infiltration of interparticle connective tissue by histiocytes, lymphocytes, and plasma cells in the liver. Membrane glomerulonephritis, granular hyaline drop dystrophy of the distal and proximal tubules’ epithelium with the formation of hyaline cylinders were found in the kidneys.