Neospora-related abortions in sheep in Israel - A serological diagnostic challenge in an endemic area

Abortions in sheep flocks is a common multifactorial problem, which affects animal productivity and welfare. Israel is endemic to several infectious abortifacient pathogens, with neosporosis identified as a prominent cause. High seroprevalence of N. caninum is present in the general sheep population, making complicate to associate it as the causative agent of abortion in sheep. Here we describe two investigations of abortion storms in sheep flocks with high seroprevalence of neosporosis. In flock A, higher anti-Neospora antibody titers were demonstrated in aborting versus non-aborting ewes, suggesting that it may be the cause of abortions. In flock B, several infectious abortifacients were identified, but only the seroprevalence of border disease differed statistically between aborting and non-aborting ewes. These reports highlight the difficulty of diagnosing the cause of abortion in a multifactorial situation, and confirm the necessity to assess paired samples from aborting and non-aborting ewes, for reliable interpretation of the results.