Atypical Myopathy Cases Reported in HorsesBy Kentucky Equine Research Staff · June 4, 2012
Equine atypical myopathy, a serious and often fatal muscle disease, has been reported from at least three countries this spring. Twenty-three horses in France, New Zealand, and England have been affected.
The disease causes degeneration of muscle fibers that leads to death from failure of the heart and respiratory system in about 90% of diagnosed horses. Early signs include sweating, twitching muscles, reluctance to move, weakness, difficulty breathing, and discolored urine.
Research has not uncovered a cause of equine atypical myopathy, though there is some evidence that toxins from Clostridium bacteria may be involved. Until the specific cause can be identified, veterinary treatment consists of supportive measures and is not always successful in preventing fatalities.