Bluetongue Disease in Ontario cattle

September 4 2015

Yesterday, the Canadian Food Inspection Agency (CFIA) informed the provincial Chief Veterinary Officers that 3 bovines were confirmed to have  Bluetongue Disease (BT) in the south western part of Ontario, approximately 100 km from the US border.  The first animal was found through the national surveillance program on a sample collected August 7th. On September 2nd two herd mates were confirmed seropositive which established that animal-to-animal transmission had occurred, as no animals on the premises had been to or in contact with animals from an endemic country. The virus was identified as serotype 13.

Up until today,  Canada has been considered free of BT; however, the Okanagan in BC has long been considered endemic for the disease. That region was set up as a compartment following a massive effort by the CFIA between 1976 and 1988, allowing the rest of Canada to retain a national disease-free status. Today, all of Canada becomes endemic for BT.

BT is caused by a virus that is transmitted between animals by biting midges (Culicoides species). It was previously thought that Ontario and Eastern Canada did not have the right vectors to transmit BT.


Information on Bluetongue can be found on the CFIA website at