Epidemiological surveillance of Neospora caninum in sheep (Ovis aries) and European mouflon (Ovis aries musimon) in southern Spain

Abstract

Neospora caninum is a protozoan with a facultative heteroxenous life cycle, with canids as the definitive hosts and other mammals, mainly ruminants, acting as intermediate hosts. This parasite is recognized as one of the major abortifacient pathogens in cattle. Although reproductive disorders have also been reported in other domestic and wild ruminants, epidemiological data on N. caninum in ruminant species other than cattle is still limited. Here, we evaluate the seroprevalence and risk factors associated with N. caninum exposure in sheep (Ovis aries) and European mouflon (Ovis aries musimon) in southern Spain. Serum samples from 390 sheep and 387 free-ranging mouflons were tested for antibodies against N. caninum using in-house time-resolved fluorescence immunoassay based on NcGRA7 as a recombinant antigen. The individual seroprevalence was 26.2 % (95 %CI: 22.0–30.7) in sheep and 5.7 % (95 %CI: 3.8–8.5) in mouflons. At least one seropositive animal was detected in all the 26 sheep farms (100 %) and in eight of the 18 (44.4 %) hunting estates sampled. The presence of dogs on the farm (≥3) and the sheep breed (purebred) were potential risk factors associated with exposure to N. caninum in sheep. Our results indicate a high circulation of N. caninum in sheep farms in southern Spain. Control measures should be implemented to limit the exposure to this protozoan in sheep flocks. Although we have confirmed for the first time the presence of anti- N. caninum antibodies in European mouflon in Spain, and, despite the relatively low seroprevalence found, the impact of this parasite on mouflon populations should be further studied.