European outbreaks of atypical myopathy in grazing equids (2006–2009): Spatiotemporal distribution, history and clinical features

Abstract

This study describes new data on case details, history and clinical course of AM that is of preventive, diagnostic and therapeutic value. However, the true impact of the findings of this study on the development of or severity of AM should be tested with case-control studies.

Atypical myopathy: an update

“…The contribution of trees (in general) to the pathogenesis of the disease was eventually suggested by van Galen and others (2012a), who found trees were present on 98 per cent of European pastures on which cases of atypical myopathy occurred. Van der Kolk and others (2010) suggested that A pseudoplatanus leaves contaminated with an endophyte (Fig 4) had a role in the aetiology of the condition but scientific evidence for this is lacking.…”

“…Horses kept at grass were suddenly presenting with an acute myopathic syndrome that was not induced by exertion; most of the affected animals died within a couple of days. Since then, outbreaks of this condition (which was later renamed atypical myopathy) have occurred sporadically in the autumn but, over the past decade, large series of cases have been observed repeatedly in several European countries not only in the autumn (Fig 1) but also in the spring (van Galen and others 2012a). Since autumn 2000, more than 1800 cases of atypical myopathy have been recorded throughout Europe by the Atypical Myopathy Alert Group (AMAG), an informal group set up in 2004 comprising veterinarians and researchers (Table 1).…”

“…For various reasons (eg, monogastric versus polygastric digestive systems), horses may be more susceptible than other species to the phytotoxin causing the condition. Epidemiological and clinical data gathered from European outbreaks suggest that donkeys and zebras may also suffer from the condition (van Galen and others 2012a). …”

“…They are frequently dyspnoeic, which often leads to death (74 per cent mortality rate [van Galen and others 2012a]). Cardiac signs are generally mild (slightly raised heart rate, heart murmurs).…”

Some notes on fatal acquired multiple acyl-CoA dehydrogenase deficiency (MADD) in a two-year-old warmblood stallion and European tar spot (Rhytisma acerinum)

“…The disease is associated with a lethality rate of up to 90% and death usually occurs within 72 hours preceded by severe (muscle) pain (Votion and Serteyn 2008). The latency period of the disease was estimated at up to four days (van Galen et al 2012).…”