Seroprevalence and associated risk factors of Neospora caninum in cattle in the Khomas region of Namibia

Abstract

Neospora caninum is a coccidian parasite which occurs worldwide and is one of the most important causes of abortion, especially in cattle. However, no studies have been done in Namibia to determine the N. caninum status in livestock. Therefore, this study aimed to determine the seroprevalence level of N. caninum in cattle and the associated risk factors in the Khomas region of Namibia. Seven hundred thirty-six (736) serum samples were collected from female cattle in 32 farming establishments. These comprised 698 beef and 38 dairy cattle sera and were tested using a commercial IDEXX Neospora X2® ELISA kit. Questionnaires were concurrently administered to determine possible risk factors associated with N. caninum seropositivity. A total of 42 sera were positive (all beef), giving an animal-level seroprevalence rate of 5.7%. Eight of the 32 establishments had at least one positive animal, giving a herd-level seroprevalence of 25%. There was no significant association between seropositivity and the presence of dogs, jackals, history of abortions, farm size, number of cattle or average annual rainfall. The establishments with moderate to high numbers of Feliformia were 9.8 times more likely to be seropositive to N. caninum than those with none to low levels of the former (p = 0.0245). The authors concluded that the seroprevalence level of N. caninum in the Khomas region was relatively low compared to other parts of the world and that the role of Feliformia in the epidemiology of bovine neosporosis needed to be further investigated.