Besnoitiosis (Bone Meal Disease)

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What causes besnoitiosis?

Besnoitiosis is caused by an intracellular parasite (Besnoitia tarandi).

Lifecycle: The parasite needs both a herbivore (eg. caribou or muskox) and a carnivore host. The parasite multiplies in the herbivore forming cysts that contain many spores. The carnivore becomes infected when it eats meat from a herbivore with cysts. The parasite comes out in the carnivore’s droppings and contaminates plants that are eaten by herbivores.

Hair loss and crusty skin on the face of a caribou infected with besnoitiosis. Photo credit: G. Wobeser, University of Saskatchewan/ Canadian Cooperative Wildlife Health Centre.

Crusty skin. Region of hair loss.

Where does besnoitiosis occur?

Besnoitia may be able to infect a wide range of ungulates (hoofed animals).

It occurs in woodland and barren-ground caribou, reindeer, and muskoxen.

In the NWT and Nunavut, besnoitiosis occurs commonly in caribou.

What are the signs of besnoitosis? Animals usually appear healthy. Heavily infected animals may lose hair on their lower legs and face, and skin may be thick. Besnoitsis can be most easily identified when skinning the lower legs. Cysts are hard and feel like a slight roughness (sand paper) over the bone and skin. Cysts appear as clear to white very small round lumps (like grains of corn meal) embedded in tissue. Similar tiny cysts may be visible on the eye.

Muskox hoof Photo credit: A. Gunn/GNWT

How can I protect myself?

You cannot get besnoitiosis from infected animals.

Can I eat the meat?

Meat from infected animals is suitable for human consumption.

Cook meat well.

Samples to collect

Lower front leg or affected tissues.