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Alaska Department of Fish and Game


Parasites and Diseases
Exertional Myopathy

A Field Guide
TO COMMON WILDLIFE DISEASES
AND PARASITES IN ALASKA

EXERTIONAL MYOPATHY

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 dfg.dwc.vet@alaska.gov or visit your local ADF&G office.