European outbreaks of atypical myopathy in grazing horses (2006–2009): Determination of indicators for risk and prognostic factors

Abstract

This study refines the list of risk factors for AM. Clinical signs valuable for diagnosis and prognosis have been identified, enabling clinicians to improve management of AM cases.

Atypical myopathy: an update

“…These measures are largely supportive and symptomatic, but it is worth noting that the only therapeutic groups that appear to be beneficial are vitamins, antioxidants (vitamins B, C and E, and selenium) and carnitine (van Galen and others 2012b); in particular, supplementation with riboflavin (vitamin B2) might improve the compromised mitochondrial function. Since atypical myopathy severely affects the energy metabolism by blocking several steps in the aerobic mitochondrial lipid metabolism (Westermann and others 2008), nutritional support is important.…”

The Story of Equine Atypical Myopathy: A Review from the Beginning to a Possible End

“…The clinical signs that were significantly more often encountered in AM-affected horses than in the non-AM group in this study were pigmenturia, normothermia, congested mucous membranes, and high serum creatine kinase (CK) values [28]. These clinical signs may be useful to strengthen a clinical suspicion of AM, but other conditions may also lead to these signs ( see above ), whereas not all AM-affected horses show them.…”

“…Epidemiological and clinical data from these cases and outbreaks have contributed to the identification of indicators or factors related to the individual horse, managemental practices, and pasture characteristics that are associated to AM [2, 3]. With these data the diagnosis of AM was improved, prognostic predictors were identified, risk and protective factors were identified, and preventive measures were recommended [28, 29]. Also, epidemiological investigations together with the contribution of specific laboratory researches have raised some etiological hypotheses and ruled out others.…”

“…Although not a case-control study, a recent European descriptive study identified that 98% of the 354 described AM cases had trees in or around the pasture. In addition, a comparison of these 354 AM cases versus sick horses reported as AM but finally classified as having another disease recognized the presence of trees, dead leaves, and dead wood at pasture as indicators of a risk factor for development of the disease [2, 28, 29]. All these findings together suggest that the implication of trees in the development of AM should be further investigated.…”

“…A recent European risk analysis compared AM-affected horses to horses that were reported to AMAG as being suspected for AM, but finally categorised as having a low likelihood of having AM or diagnosed with another condition (non-AM group) [28]. Because this comparison points out the difficulties of correctly diagnosing AM, differences between groups are not only indicators of risk factors, but are also of diagnostic aids.…”