Successful treatment of suspected exertional myopathy in a rhea (Rhea americana).

A 7-yr-old, adult, female greater rhea (Rhea americana) from the National Zoological Park presented with a 24-hr history of severe left leg lameness that progressed to an inability to stand. Blood work revealed creatine phosphokinase (CPK) above 50,000 U/L and elevated lactate dehydrogenase. The bird's condition deteriorated over the next week. The bird's CPK increased to over 208,400 U/L. Aggressive intravenous fluids and physical therapy along with oral anxiolytic and muscle-relaxant drugs were instituted. After 2 wk of aggressive therapy, initial signs of improvement were noted. By day 28, the bird was able to walk unassisted with no noticeable lameness. This is one of the few reported cases of successful treatment of suspected ratite exertional myopathy. It is believed that success in this case can be attributed to persistent, aggressive physical therapy, muscle relaxants, and anxiolytics aimed to counteract the hyperexcitable nature of these birds.