Capture myopathy in pronghorns in Alberta, Canada.

From 1971 to 1975, inclusive, 594 pronghorns (Antilocapra americana) were drive trapped in Alberta; subsequently, 74 of these animals were transported to enclosures. Deaths attributable to capture myopathy (CM) occurred in 20 of the trapped pronghorns and in 17 of the pronghorns that were trapped and subsequently transported. Two neonatal pronghorns that had been pursued died with signs and lesions similar to those seen in adult pronghorns affected with CM. The diagnosis of CM was based on history, clinical signs, clinico-pathologic findings, and gross and histologic lesions. Clinical signs of CM included depression, stiffness, weakness, incoordination, recumbency, and paralysis; myoglobinuria was observed in 1 neonatal animal. Of the pronghorns that died, fewer than one-half died acutely during processing, whereas the remainder died from 1 to 13 days following their release. Gross and histologic lesions were observed in the large muscles of the hindlimbs of most affected pronghorns. Values for serum enzymes, potassium, glucose, and creatinine, were higher for drive-trapped pronghorns than for tame, hand-reared pronghorns. These findings indicated extensive damage to muscle and to other organs as a result of the capture procedures.