Abortion epidemic in a dairy herd associated with horizontally transmittedNeospora caninuminfection

Abstract

A dairy herd experienced an abortion epidemic during which 43 per cent of the cows at risk aborted. Neospora caninum infection was demonstrated in four of six fetuses suitable for examination and the group of at-risk cows that aborted had significantly higher N. caninum antibody concentrations than the at-risk cows that delivered a live calf at term (P<0.001). The antibody concentrations in the cow herd were significantly higher than in the youngstock (P<0.001), and the concentrations in the youngstock increased significantly (P<0.001) with age. When seven months to a year old, the calves born at term to the at-risk cows had significantly higher (P=0.007) antibody concentrations than age-matched calves born before the epidemic. At the time of the epidemic, there was a significant increase in the antibody levels of the herd that was not consistent with vertical infection alone, indicating that there appeared to have been a sudden large increase in the incidence of horizontal postnatal transmission of N. caninum to the cow herd, or to the surviving offspring of the at-risk cows, or to both of these groups.

Detection ofNeospora caninumin aborted bovine fetuses and dam blood samples by nested PCR and ELISA and seroprevalence in Beijing and Tianjin, China

“…The parasite can infect a broad range of warm-blooded animals (Anderson et al 2000; Dubey, 2003; Dubey and Lindsay, 1996; Moore, 2005), but only dog (McAllister et al 1998) and coyote (Gondim et al 2004) are the definitive hosts. Cattle are the intermediate host, and N. caninum infection causes repeated abortions, stillbirths and vertical infection of calves (Anderson et al 2000; Crawshaw and Brocklehurst, 2003; Huang et al 2004).…”

An Abortion Storm in Cattle Associated with Neosporosis in Taiwan

“…In our previous serological survey for antibodies against N. caninum in Taiwan, we reported that 23% (3/13) of the farm dogs in Taiwan were sero-positive [17]. Thus, control of dogs in cattle farm should be considered as a measure to prevent neosporosis-associated abortion in the farm, especially preventing the dogs from eating the aborted fetus [5,7,10]. Furthermore, we also recommended that neosporosis sero-negative dairy farm should be identified and the cattle serologically tested at a regular interval to prevent suspected neosporosis-associated abortion storm.…”