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Parasites and Diseases
Exertional Myopathy

A Field Guide


Dall sheep shoulder and leg
Shoulder blade and leg of Dall Sheep. Diminished muscles due to myopathy.

What causes exertional myopathy?
  • Exertional myopathy is a muscle disease that can occur when wild animals are chased, handled or stressed.

Where does exertional myopathy occur?
  • It is most commonly seen in ungulates (hoofed animals) like moose and caribou, but has been reported in a wide variety of wild animals and birds.
  • It can occur whenever animals are chased or handled.

What are the signs of exertional myopathy?
  • Animals may appear depressed, weak and stiff.
  • The muscles, heart and kidney are usually affected but signs may be difficult to see.
  • There may be differences in the color and textures of muscle groups.
  • Early in the disease, affected muscles may look wet and have small bruises.
  • Later, the muscle becomes pale, dry, and very soft.
  • In severe cases, entire muscles may be torn.
  • The heart muscle may have pale areas or streaks.
  • Lungs are usually dark and wet.
  • In bad cases, the bladder may contain red-brown urine and kidneys may be dark brown.

Can I eat the meat?
  • Meat from affected animals is suitable for human consumption.
  • Exertional myopathy may cause muscle changes that decrease the quality of the meat.

Samples to collect
  • Portions of muscle from several different areas of the body, as well as sections of the heart and kidney.
  • Samples should be kept cool but not frozen.
  • To report an occurrence or to submit a sample for identification/analysis, contact the DWC Wildlife Disease Surveillance reporting hotline 907-328-8354, send an email to or visit your local ADF&G office.