Atypical Myopathy: 100+ Cases Diagnosed Worldwide in 2011

More than 100 horses worldwide were diagnosed with atypical myopathy in 2011, according to an alert from the European-based website

"At the date of the Dec. 23, 2011, 116 clinical cases compatible with the diagnosis of atypical myopathy have been communicated to Liège University (in Belgium, the location of a great deal of atypical myopathy research) and to the RESPE (Réseau d'Epidémio-Surveillance en Pathologie Equine, or the Epidemiological Surveillance Network for Equine Diseases)," the alert reads.

The cases were reported in the following nations:

  • France--34 cases;
  • Great Britain--34 cases;
  • Germany--19 cases;
  • Belgium--16 cases);
  • Switzerland--6 cases;
  • Austria--3 cases
  • United States--3 cases; and
  • Canada--1 case.

Atypical myopathy, a seasonal, pasture-associated muscle disorder of unknown etiology (cause), presents a particular challenge to veterinarians. The disease is characterized by a generalized complete degeneration of muscle fibers, which leads to sudden death due to the collapse of the cardiorespiratory system in more than 90% of cases. The economic impact is often devastating.

Affected horses can either die peracutely (acutely) or show profuse sweating, muscle fasciculation (twitching), weakness, pigmenturia (urine discoloration), reluctance to move, recumbency (inability to stand), difficulty breathing, and death after 12-72 hours. Since the etiology is unknown, no effective prophylaxis (preventive treatment) exists and affected horses can only be treated symptomatically.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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