Risk Factors Associated with Neospora caninum Herd Serological Status in Beef Cow-Calf Herds in Canada

Abstract

Neospora caninum (N. caninum), a protozoan parasite, is a major cause of reproductive failure in cows all over North America and in other regions of the world. Infected cows are at risk of early embryonic death, abortion, stillbirth, birth of a weak or abnormal calf and birth of a calf with no obvious defect, depending on previous exposure and the phase of gestation-early, mid or late. The dog has been implicated as a definitive host of N. caninum and contributing to fecal-oral (horizontal) transmission. It has been suggested that neonates become infected while in-utero (vertical transmission). The role of wild canids, coyotes and foxes in transmitting infection in beef cow-calf is still not clear. Although suggested, it is not known if extensive husbandry and management methods employed in beef cow-calf plays a role in N. caninum infection, transmission and disease occurrence in beef cow-calf herds. The objective of this study was to determine seroprevalence of N. caninum in beef cow-calf herds in Canada and to identify potential risk factors contributing to seroprevalence.