Seroepidemiology of Neospora caninum and Toxoplasma gondii infection in yaks (Bos grunniens) in Qinghai, China

Neospora caninum is a protozoan parasite and is closely related to Toxoplasma gondii, but they are antigenically different. N. caninum and T gondii infection in a variety of animals such as cattle, dogs, and cats has been reported, but there is little information on the infection of these parasites in domestic yaks. Seroprevalence of antibodies to T gondii and N. caninum in yaks (Bos grunniens) from eight regions of Qinghai, China were investigated by the indirect agglutination test (IAT) and ELISA, respectively. A total of 112 (11.8%) of 946 serum samples were positive for antibodies to T gondii, and 21 samples (2.2%) were positive to N. caninum. Two of the yaks had antibodies to both parasites. There was no apparent association of T gondii infection with age of the animals. The results indicate that T gondii infection is prevalent in Chinese yaks in most parts of Qinghai province and N. caninum infection rate in the same species is relatively low. This is the first large study showing the infection of T gondii and N. caninum in domestic yaks. (C) 2007 Elsevier B.V. All rights reserved.