Editor’s note: This article is part of TheHorse.com’s ongoing coverage of topics presented at the 2012 American College of Veterinary Internal Medicine Forum, held May 30 – June 2 in New Orleans, La.


One health condition of horses that necessitates quick identification and action on the owner’s part is acute rhabdomyolysis ("tying up"), an ailment that, if left unattended, can progress to the point of requiring euthanasia. At a recent veterinary conference, one researcher gave an overview of how to identify and manage episodes of "tying up."

"Severely affected horses can present a challenging medical situation, and evaluation should include attempts to identify the probable underlying cause of disease to ensure that thorough and appropriate treatment is provided," explained Erica C. McKenzie, BSc, PhD, Dipl. ACVIM, Dipl. ACVSMR, associate professor of large animal medicine at Oregon State University. She presented the lecture at the 2012 American College of Veterinary Internal Medicine Forum, held May 30 – June 2 in New Orleans, La.

Before delving into identification and treatment, McKenzie discussed a few causes of rhabdomyolysis.

Causes

McKenzie said that rhabdomyolysis can be caused by either "exertional or non-exertional phenomena." Exertional causes include:

  • Polysaccharide storage myopathy (PSSM, most commonly seen in Quarter Horses and related breeds often associated with a mutation of the glycogen synthase 1 gene); and
  • Recurrent exertional rhabdomyolysis (RER, a calcium regulation disorder seen com