 Rhabdomyolysis affecting horses may also occur in outbreaks ; these have been reported in many European countries , and later in Canada , Australia , and the United States . It has been referred to as " atypical myopathy " or " myoglobinuria of unknown etiology " . No single cause has yet been found , but various mechanisms have been proposed , and a seasonal pattern has been observed . Very high creatine kinase levels are detected , and mortality from this condition is 89 % . 
