Associated risk factors influencing ovine Eimeria infections in southern Spain

Abstract

Eimeria infections are common in sheep industry worldwide nonetheless very little is known on infection dynamics and associated risk factors influencing the outcome of clinical ovine coccidiosis. The aim of the present work was to analyse intrinsic (e. g. host age) and extrinsic (flock size, farm size and animal density) risk factors influencing dynamics of Eimeria spp. infections in sheep farms of the semi-arid region of Murcia in southern Spain. Overall, 64 ovine flocks in Murcia were surveyed and a total of 396 faecal samples were collected between May and July 2015. Flotation and McMaster techniques were performed for parasitological investigation. Excreted oocysts were identified on the basis of morphological as well as morphometric characteristics. In all analysed samples Eimeria spp. oocysts (100%) were found and 11 different Eimeria species were identified. Most prevalent species was E. ovinoidalis (97%) followed by E. parva/E.pallida (97%), E. weybridgensis (90.9%) and E. crandallis (89.4%), respectively. Concomitant infections with more than one Eimeria species were observed in all analysed samples. Analysis of intrinsic/extrinsic risk factor revealed age, herd/farm size and animal density to be the main factors significantly influencing Eimeria oocysts per gram of faeces counts (OPG) and overall prevalence of Eimeria spp. infections in sheep.

Keywords: Coccidiosis; Eimeria; Intrinsic and extrinsic factors; Ovine; Risk factors.