Prevalence and Pathogen Profiles of Yak Diarrhea in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China

Yak diarrhea is a major health concern in high-altitude regions, yet data are lacking in Ganzi Tibetan Autonomous Prefecture, a key yak-producing area in China. This study aimed to describe the prevalence, mortality, seasonal patterns, and pathogen profiles of yak diarrhea in Ganzi Prefecture. Between 2017 and 2024, surveys were conducted across 5 counties, involving 5 cooperatives and 62 households. Fecal and blood samples were collected from healthy (n = 1805) and diarrheic yaks (n = 189) for pathogen detection. Among 1.9066 million yaks, breeding females accounted for 48.48% and calves 26.32%. Diarrhea prevalence was 12.22% in adult yaks and 20.91% in calves, with mortality rates of 15.71% and 28.29%, respectively. Cases peaked in spring and winter. Pathogen detection in healthy yaks revealed intestinal parasites (43.26%) and BVDV (2.33%). In diarrheic yaks, higher rates were observed for intestinal parasites (46.56%), E. coli (10.05%), Salmonella (10.58%), BVDV (22.75%), and Theileria (25.40%). Mixed infections were common. These findings provide a descriptive baseline for guiding region-specific control strategies.