Diagnosis and Control of Bovine Neosporosis.

Neosporosis is one of the most common and widespread causes of bovine abortion. The causative parasite is transmitted in at least two ways, horizontally from canids, and by endogenous transmission within maternal lines of infected cattle. The prevalence of neosporosis is higher in the dairy industry than in the beef industry because of risk factors associated with intensive feeding. There are no vaccines, but logical management options are discussed that can lower the risk of abortion outbreaks and gradually reduce the prevalence of infection within herds. Steps should be taken to prevent total mixed rations from becoming contaminated by canine feces. If a herd has a high rate of infection that is associated with abortions in heifers, then the rate of reduction of infection prevalence can be speeded by only selecting seronegative replacement heifers to enter the breeding herd. Elimination of all infected cattle is not a recommended goal.