Histopathological Changes in Some Vital Organs of Nursery Pigs in Mortalities Associated with African Swine Fever Outbreak

Abstract

African swine fever (ASF) is a contagious viral disease that affects domestic and wild pigs. The disease is of serious economic importance as outbreaks lead to the culling of millions of pigs in Africa, Eastern Europe and some parts of Asia. The present study evaluated the histopathological changes in some visceral organs in nursery pigs infected with ASF virus. The pigs were euthanized in carbon dioxide chamber and necropsied. Tissue samples were fixed in 10% neutral buffered formalin, routinely processed, sectioned at 5µm thickness and stained with hematoxylin and eosin (H&E). Results showed petechial and ecchymotic hemorrhages grossly on the skin and in the lungs, heart, spleen, lymph nodes, and kidneys. In the heart, there was hydropericardium and the pericardial sac was cloudy. The liver was also enlarged and mottled. Microscopically, hemorrhages were present in the lungs, heart, lymph nodes, and kidneys. There was interstitial pneumonia and necrosis of renal tubules. Severe lymphoid necrosis occurred in the spleen. It was concluded that the disease involved a moderately pathogenic isolate of ASF virus and that hemorrhages in visceral organs and destruction of lymphoid tissues remained the major findings in sub-acute ASF infection.