Prevalence study of bovine fascioliasis in some selected LGA in Osun State, Nigeria

Introduction Bovine fascioliasis is an economically important parasitic disease that continues to affect cattle production in many tropical and subtropical regions. This study investigated the prevalence, distribution, infection intensity, and associated epidemiological factors of fascioliasis among cattle slaughtered in selected abattoirs across six Local Government Areas of Osun State, Nigeria, between January and December 2025. Methods A total of 151 cattle and 69 liver samples of different breeds and sexes were examined using post-mortem liver inspection, bile sedimentation, egg count analysis, and recovery of newly excysted juveniles (NEJs) and adult liver flukes. Descriptive and inferential statistical analyses were employed to assess infection patterns and associated risk factors. Results An overall prevalence of 63.58% was recorded, indicating that fascioliasis remains endemic in the study area. Infection was detected throughout the study period, with monthly prevalence ranging from 41.67% to 80.00%. Higher prevalence and infection intensity were generally observed during the rainy season, highlighting the influence of environmental conditions on parasite transmission. Across Local Government Areas, prevalence ranged from 58.33% to 68.75%, with no significant geographical variation. All major cattle breeds examined were susceptible to infection, although Fulani and Bokolo cattle exhibited relatively higher prevalence and egg counts. Male cattle showed slightly higher prevalence (64.63%) and mean egg counts than females (62.31%). Egg count analysis revealed substantial variation in infection intensity among animals, with higher mean egg counts recorded during the wet season than the dry season. Parasitological examination yielded 73 adult liver flukes and 32 newly excysted juveniles, confirming active and ongoing transmission of the parasite. Statistical analysis showed a significant association between Fasciola egg detection and sex (p = 0.015), while breed, liver fluke burden, bile colour, NEJ counts, and Local Government Area showed no significant associations. Conclusions The findings demonstrate that bovine fascioliasis remains widespread in Osun State and is strongly influenced by environmental and management-related factors. Integrated control measures involving strategic deworming, improved grazing management, snail habitat control, and strengthened surveillance are essential for reducing transmission and minimizing economic losses associated with the disease.