Sarcocystosis cysts embedded in muscle tissue.

Muscle sample of an animal with sarcocystosis.

What causes sarcocystosis?

Sarcocystosis is caused by the cyst stage of a single-celled parasite.

Lifecycle:   The parasite needs a herbivore in the muscles.  The carnivore becomes infected when it eats meat from a herbivore with cysts.  The parasite reproduces in the carnivore’s intestine without harming the animal.  It comes out in the carnivore’s droppings and contaminates plants that are eaten by herbivores.
 

Where does sarcocystosis occur?

Sarcocystosis occurs in many wild ungulate species (hoofed animals) including bison, caribou, reindeer, moose and Dall’s sheep.

In the NWT and Nunavut, sarcocystosis occurs commonly in barren-ground caribou.
 

What are the signs of sarcocystosis?

Animals usually appear healthy.

When butchering infected caribou, cysts may be found in muscle tissue.

Cysts may look like grains of rice (whitish streaks) running in the direction of muscle fibres.

They may not be visible (usually less than 1 mm long), but  can reach 5 mm in length and be seen in the meat.

Larger cysts may lie loose in the connective tissue surrounding muscle and can be oval or globular in shape.

Animals may have swollen muscles with greenish cigar-shaped areas up to several centimetres in diameter caused by decomposing cysts.
 

How can I protect myself?

You cannot be infected by the cysts of Sarcocystis spp. in meat.

The form of the parasite found in carnivore droppings may be infective. Be careful if handling carnivore droppings.
 

Can I eat the meat?

Meat from infected animals is suitable for human consumption.

Cooking will kill the parasite.

Do not feed infected meat to dogs.
 

Samples to collect

heart, tongue, diaphragm and skeletal muscles