Use of Bulk Tank Milk to Determine the Herd-level Prevalence of N. caninum in Dairy Herds on Prince Edward Island

Abstract

The apicomplexan protozoan parasite Neospora caninum is one of the most frequently diagnosed causes of bovine abortion. Transmission of the parasite occurs vertically from cow to calf with great efficiency, sustaining the infection within cattle herds for many generations. The herd-level prevalence of N. caninum on PEI is estimated to be 20.3%. This is relatively high compared to other Canadian provinces and research is needed to aid in the control of this infection on dairy farms. Serology is the only method available to diagnose N. caninum infection in live animals, but herd surveillance, using serology, is expensive and time consuming, especially in large dairy herds. The use of milk as a diagnostic tool could be very beneficial to the dairy industry, as it would allow for a fast and inexpensive way to test herds for N. caninum exposure. Furthermore, because the majority of dairy herds in PEI collect milk samples monthly (DHI; Dairy Herd Improvement), Neospora surveillance using milk would result in less stress on the lactating cow, and no special visits would be required to collect samples.