The Relationship of Abortion, Dog Management and Neospora caninum in Dairy Herds in Taiwan

Abstract

Neospora caninum (N. caninum) has caused an abortion storm in dairy herds for two decades in Taiwan. There is no effective medicine for N. caninum infection for livestock, therefore, prevention by farm management is very important. The risk factors for N. caninum infection in Taiwan is still unclear. Dogs are the common definitive hosts of N. caninum on farms. This study aims to estimate the sero-prevalence and detection of N. caninum DNA in 361 pregnant dairy cows and establish an effective strategy to prevent abortion caused by N. caninum in dairy farms in Taiwan by logistic regression. The sero-prevalence of N. caninum was 26.3% (95/361) and 75% (24/32) in cows and farms, respectively. The positive rate of N. caninum DNA detection in blood by semi-nested polymerase chain reaction (PCR) and real-time PCR was 2.2% and 17.2%, respectively. There were twelve dairy herds with an abortion rate >5%. Seven farmers claimed to have had severe abortion issues on their farms, of which, six had an abortion rate >5%. Sero-positivity was significantly higher in cows with an abortion history. The presence of domesticated dogs was negatively associated with sero-positivity of N. caninum, whereas free-roaming dogs in the farm area were positively associated with sero-positivity of N. caninum. In conclusion, managing free-roaming dogs is an efficient approach to reducing the sero-prevalence of N. caninum infection in dairy herds and N. caninum infection is one of the major factors causing abortion in dairy herds in Taiwan.