European outbreak of atypical myopathy in the autumn 2009.

Background: Atypical myopathy (AM) is an acute, severe rhabdomyolysis occurring in grazing horses. Since In the beginning of October 2009, a new outbreak affects started in several European countries. Geographic, demographic and clinical data of the reported cases in the month October 2009 are described.
Key Findings: The survival rate over the month October 2009 was 25%. The most frequently observed clinical signs were congestedive mucous membranes, dyspnea, tachycardia, depression, weakness, stiffness, recumbency, trembling, transpirationsweating, and myoglobinuria. Non-survivors were significantly more often likely to be recumbent than survivors. Prognostic factors, symptomatic treatment and preventive measures are discussed.
Significance: Slight differences were encountered during the described outbreak of AM in October 2009 compared to previous studies. Equine practitioners should be alert aware that previous epidemiological studies have shown that after a high prevalence this autumn, for new cases are likely to occur in the upcoming spring 2010.