On April 9th, a barren-ground caribou was discovered attacking equipment unprovoked in Coral Harbour, Nunavut. Based on the aggressive disposition of the caribou, it was euthanized and the Government of Nunavut was able to ship the head to the CWHC for examination. The brain tested positive for rabies on our preliminary dRIT rabies test and was sent to the CFIA for confirmatory testing. The brain tested positive for rabies at CFIA by fluorescent antibody test (FAT) and the virus was confirmed to be arctic fox strain rabies.
Rabies is a fatal neurological disease caused by the rabies virus and is transmitted through the saliva of an infected animal, most commonly via bite or scratch1. Rabies can affect all mammals, including humans, and the disease is nearly 100% fatal once clinical signs are observed1. The most well-known clinical sign observed in infected animals is aggressive behaviour. However, this is not always the case. Rabies can manifest in one of two forms: furious or dumb1. In the furious form, the animal may display extreme excitement or classic aggression, while the dumb form is characterized by the animal’s depressive nature, lack of fear towards humans, and potentially partial paralysis1. This paralysis can lead to drooling, abnormal facial expressions, strange sounds, and other related motor impairments1. An animal may exhibit symptoms of both forms1.
Although rare, this is not the first case of rabies found in the northern caribou population2. Caribou are not considered to be one of the main reservoir hosts for rabies — that is to say, they do not play a crucial role in maintaining and spreading the virus, but any infected animal can potentially spread the virus to another host. There have been 5 confirmed cases of rabies in Nunavut so far in 20255 and this caribou likely became infected through the bite of an infected arctic fox. In the Canadian Arctic, the primary natural reservoir host species for rabies is the arctic fox, followed distantly by the red fox. Outside of the Arctic, the primary reservoir species in Ontario are bats, raccoons, skunks, and red foxes3,4 . But it is important to remember that any mammal can potentially be infected with rabies.
If you come across any wildlife exhibiting symptoms of rabies, do not approach. Contact your local animal services for help. If you think you may have been in contact with a potentially rabid animal, please reach out to your health care provider or your local public health unit as soon as possible to discuss next steps. If your domestic animal has been in contact with a potentially rabid animal, please reach out to your veterinarian.
References
- Government of Ontario. (2025, April 15). Rabies in Wildlife. https://www.ontario.ca/page/rabies-wildlife
- Government of Nunavut. (2022, January 04). Rabies: What you should know. https://www.gov.nu.ca/sites/default/files/publications/2022-01/RabiesBrochure_ENG_5.pdf
- Burns, J. E., Mhapankar, G., Kilabuk, E., & Penner, J. (2025). Zoonotic infections of the Canadian Arctic. Canadian Medical Association Journal, 197(2), E34–E43. https://doi.org/10.1503/cmaj.240541
- Government of Ontario. (2025, March 31). Rabies. https://www.ontario.ca/page/rabies?
- Government of Canada, Canadian Food Inspection Agency. Rabies cases in Canada 2025. https://inspection.canada.ca/en/animal-health/terrestrial-animals/diseases/reportable/rabies/canada/rabies-cases-2025