Helminths, Ticks, and Calf Mortality in Ethiopia: A Prospective Cohort Study

There is a significant demand for animal products in Ethiopia, driven by the country's rapid urbanization and population growth. In contrast, calf death has been hindering cattle productivity. This study investigated helminth and tick species affecting calves and evaluated whether calf mortality exceeded accepted management thresholds. The purposes of this study were to accurately identify tick and helminth species present in collected samples, to quantify morbidity and mortality rates, and to determine the prevalence of helminth infection and tick infestation. From January to December 2024, a prospective cohort study using a cluster-randomised sampling design was conducted on calves aged up to 1 year. The study population was clustered into semi-intensive and smallholder dairy farms. More than half (57.6%, 95% CI: 0.5287-0.6230) of the fecal samples tested positive for helminth parasite eggs of various species. Different tick species were observed on 92% (95% CI: 0.8912-0.9432) of the calves examined. Mortality rate was 15.08% and significantly associated with locations and higher in Bedele (OR = 2.9, p = 0.029, 95% CI: 1.21-7.04), Didessa (OR = 2.6, p = 0.037, 95% CI: 1.14-5.98), semi-intensive production system (OR = 3.97, p = 0.015, 95% CI: 1.31-11.72), rainy season (OR = 4.8, p = 0.008, 95% CI: 2.39-10.56), and greater herd numbers (OR = 5.62, p = 0.001, 95% CI: 2.72-12.25). The projected crude mortality rate was high, and awareness-raising should be undertaken to reduce the social and economic impact on owners' livelihoods. All stockholders should implement strategic deworming with broad-spectrum anthelmintics to control helminth species and use effective acaricides to control tick infestations.