UTTAR PRADESH JOURNAL OF ZOOLOGY

Fascioliasis, caused by Fasciola gigantica, is an important parasitic disease affecting livestock in tropical regions and is associated with significant economic losses due to reduced productivity and condemnation of infected organs. This study investigated the prevalence of Fasciola gigantica and the associated histopathological changes in pig livers in Delta Central Senatorial District of Delta State, Nigeria. A total of 741 pigs were examined over a 12-month period (April 2023–March 2024). Altogether, 1,478 samples comprising faecal and gall bladder contents were collected and analysed using standard flotation and sedimentation techniques, while liver tissues were processed for histological examination using hematoxylin and eosin staining. Out of the samples analysed, 837 were positive for one or more parasites, giving an overall prevalence of 56.6%. Fasciola gigantica was detected in 361 of 1,064 faecal samples (33.9%) and 112 of 413 gall bladder samples (27.1%). Histopathological examination of infected liver tissues revealed marked pathological alterations, including centrilobular hepatocellular necrosis, hepatocellular degeneration, inflammation, and fibrosis of the hepatic parenchyma. Microscopic observations further showed distorted hepatocytes, necrotic tracts associated with fluke migration, biliary proliferation, and infiltration of inflammatory cells such as lymphocytes, macrophages, and eosinophils within the portal areas. These lesions indicate severe tissue damage resulting from the migratory activity of immature flukes and the prolonged presence of adult parasites in the bile ducts. The findings demonstrate that Fasciola gigantica infection is prevalent among pigs in the study area and causes significant histopathological damage to the liver. Effective parasite control strategies and improved veterinary surveillance are therefore essential to reduce infection rates and enhance pig production in the region.