By: Dr. Jocelyn Jansen, OMAFRA; Dr. Maria Spinato, Animal Health Laboratory; Dr. Paula Menzies, Ontario Veterinary College During the latter half of December 2015 and the start of 2016, the Animal Health Laboratory (AHL) received several submissions of stillborn and aborted lambs with unusual and severe birth defects. Other similar cases were also reported to OVC and OMAFRA veterinarians. The most likely cause of these birth defects is Cache Valley virus (CVV). Blood and tissue samples from fetuses, as well as blood samples from ewes, were tested for the virus and/or antibodies to CVV. On January 14, 2016, test results came back positive for CVV. CVV was previously diagnosed in Ontario flocks in 2011, 2012 and 2013. CVV is…
