Systematic review and meta-analyses of the effects of halofuginone against calf cryptosporidiosis.

Halofuginone seems to reduce diarrhoea and oocyst shedding in calves with cryptosporidiosis, but provides no complete cure. To develop more precise estimates of the effects of halofuginone on calf cryptosporidiosis, meta-analyses were performed, including studies on prophylactic and therapeutic treatment. Meta-analysis increases statistical power because several trials are evaluated together, increasing the effective sample size and possibility of detecting true effects. In total, 20 cohort or clinical studies (in 16 publications) investigating halofuginone treatment in calves were identified. One study was excluded because treated calves and control calves were not investigated in parallel. Four studies (three publications) were excluded because only abstracts were available. Thus, 15 studies from 12 publications, with 10-311 calves were included for data extraction. Of these, five studies from three publications could not be used for meta-analysis because they did not report the data needed. Effects on infection prevalence, diarrhoeal prevalence and mortality were investigated. For prophylactic treatment, halofuginone had an effect on infection and diarrhoeal prevalence on study days 4 and 7, but the control group had significantly lower infection prevalence than the halofuginone treated group on study day 21. Heterogeneity was detected on study days 14 and 21 and publication bias was detected on study days 7 and 14. Mortality was not affected. For therapeutic treatment, a shortage of studies in combination with heterogeneity made interpretations uncertain, and we could not determine if halofuginone treatment benefits calves.