Management-associated herd-level risk factors for cryptosporidiosis in dairy calves in Finland.

INTRODUCTION: Cryptosporidiosis is a prevalent diarrheal disease in young calves caused by the zoonotic protozoan parasite Cryptosporidium parvum. The etiology of the disease is multifactorial. This case-control study investigated herd-level risk factors associated with clinical cryptosporidiosis on dairy farms. METHODS: The case farms (n=77) were Finnish dairy farms with clinical, laboratory-confirmed cryptosporidiosis and the control farms (n=152) were Finnish dairy farms without any recent clinical calf diarrhea outbreaks recorded in the most recent veterinarian's herd health visit. Control farms were not tested for the presence of C. parvum. Data were collected on overall herd health, management practices, environmental factors, and other factors potentially affecting the care of the calves. The data were analyzed with multivariable logistic regression. RESULTS: The results indicate that a large herd size, cattle transfers between farms, insufficient isolation of sick calves from healthy ones, insufficient time for calf care, and five or more individuals involved in daily cattle work were all associated with increased risk of cryptosporidiosis. DISCUSSION: The findings of this study suggest that several herd-level management factors were associated with the occurrence of cryptosporidiosis on dairy farms, and the external and internal biosecurity of farms should be improved. Information on potential factors predisposing to cryptosporidiosis can be used to target preventive management practices more effectively on cattle farms to prevent cryptosporidiosis in calves.