Atypical myopathy: a review and description of the outbreak in the Netherlands during autumn 2009 and spring 2010.

This research article provides a comprehensive overview of equine atypical myopathy (AM), a severe horse disease that can cause considerable damage to the muscles. It also presents specific data from an outbreak that occurred in the Netherlands during the autumn of 2009 and spring of 2010.

Understanding Atypical Myopathy (AM)

• This paper explores the condition known as atypical myopathy (AM), an acute and severe condition affecting the muscles of horses that can lead to a breakdown in the muscle tissues, a condition known as rhabdomyolysis.
• The paper provides a review of the existing literature on this topic, helping to collate current knowledge on the prevalence, mortality rates, clinical signs and pathology of AM. This includes the potential causes or triggers of the condition, the typical aspects found in cases of the disease, and how it is diagnosed and treated. The likely outcomes or prognoses for horses suffering from AM are also covered.
• The authors also discuss wider issues around horse care and management, and shine a light on the environmental factors which may contribute to occurrences of AM. This includes looking at typical weather conditions that correlate with the disease and discusses potential measures that could be taken to prevent the condition.

Outbreak in the Netherlands

• The paper also gives particular focus to an outbreak of AM that took place in the Netherlands during autumn 2009 and spring 2010.
• The researchers carefully collected data on 54 cases of horses that were highly likely or confirmed to have developed AM during this period. This included 27 horses affected in autumn and the same number affected in spring.
• The authors reveal that affected horses include nineteen mares, eleven geldings, and eight stallions, with the sex of the remaining sixteen horses not recorded. The mortality rate among these horses was found to be 74.5% – roughly mirroring rates found in prior studies on the disease.
• The article also notes that a large number of these cases were reported at roughly the same period.
• Interestingly, the authors noted that 35 of these horses had been grazing near maple trees. This included fifteen cases where the maple trees were known to have been infected by the fungus Rhytisma acerinum – placing potential ecological and environmental factors in relation to the outbreak of AM in these particular circumstances.