Abstract

A systematic review and meta-analysis was conducted with the aim to measure the prevalence of anthelmintic resistance (AR) in cattle gastrointestinal nematodes (GIN) and potential management factors associated with development of such resistance. A search algorithm was constructed and a comprehensive search of the primary literature was conducted in: CAB abstracts (1990-2016), Medline (1860-2016), Agricola (1924-2016) and Lilacs (1985-2016). Prevalence estimates were combined through meta-analysis (MA) using the logit prevalence and between-study heterogeneity was quantified. Twenty-nine publications (5 cross-sectional studies; 14 prevalence surveys and 10 field trials) were included in this review. Random effects MA resulted in an overall AR prevalence of 72.0% (95% CI=58.4% to 80.0%). However, a high heterogeneity was observed (I²=55.9%). From studies reporting the nematode genera involved in the AR, Cooperia spp were present in 91.7% of the studies (n=24); Ostertagia sp. in 44.5% (n=22); Haemonchus sp. in 47.8% (n=23); Trichostrongylus sp. in 36.4% (n=22) and Oesophagostomum spp. in 23.8% (n=21). The included cross sectional studies suggested that frequency of treatments, age of cattle and type of management were potential management factors associated with AR in bovine GINs. However, more detailed studies are necessary to fully evaluate management guidelines for implementation of sustainable GIN control strategies.

Keywords: Ruminants; Parasites; Resistance establishment; Risk factors; Meta-analysis