Assessment of Prevalence of Clinical and Subclinical Mastitis in Dairy Cattle in West Arsi Zone, Ethiopia

This study was conducted to assess the prevalence of both clinical and subclinical mastitis in lactating dairy cows in selected districts of the West Arsi Zone, Ethiopia. A cross-sectional study was conducted on 200 lactating cows across 40 dairy farms. Clinical mastitis was diagnosed via physical examination, while subclinical mastitis was detected using the California Mastitis Test (CMT). Overall mastitis prevalence was 41.5%, including 9.5% clinical and 32% subclinical. Crossbred cows showed the highest prevalence (51.8%), followed by local (26.5%) and exotic breeds (21.7%). Older cows (>9 years) and cows in late lactation stages exhibited significantly higher mastitis rates. Risk factors included breed, age, parity, lactation stage, production system, and hygiene practices. The study underscores a high burden of subclinical mastitis and the critical influence of management and hygiene. Control efforts should focus on early detection, improved milking hygiene, and better cow housing.