Neospora causes abortions in cattle worldwide, and is the leading cause of abortions in California dry lot dairies. Until recently, its definitive host — or carrier animal where the parasite completes its life cycle — was unknown. But now, a research team led by veterinary researcher Milton McAllister, University of Wyoming, has identified dogs as the definitive host of Neospora caninum.

The study, published in volume 28 of the 1998 International Journal for Parasitology, lists dogs as the definitive host and suggests that producers should try to keep pet dogs and strays from defecating in dairy feedlots or pastures. In addition, care must be taken to prevent pregnant animals from ingesting feces-contaminated feed. Doing so will help prevent the transmission of the parasite to the fetus via the placenta.

Consult your veterinarian to develop a prevention plan for your dairy.