Survey of the equine broodmare industry, abortion, and equine herpesvirus-1 vaccination in Ontario.

A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The odds of having respiratory illness on the farm were significantly greater if the farm was the primary source of income even after controlling for farm size. Respondents with primary breeding operations were more likely to utilize vaccines against equine herpesvirus 1 (EHV-1), independent of herd size. Veterinarians were more involved with abortions than with respiratory disease, leaving a significant gap in the opportunities for client education.