title: European outbreaks of atypical myopathy in grazing equids (2006-2009): spatiotemporal distribution, history and clinical features.
abstract: BACKGROUND
  Improved understanding of the epidemiology of atypical myopathy (AM) will help to define the environmental factors that permit or support the causal agent(s) to exert toxicity.
  
  
  OBJECTIVE
  This European survey of AM aimed to describe spatiotemporal distribution, survival, clinical signs, circumstances in which AM develops and its different expressions between countries and over time.
  
  
  METHODS
  The spatiotemporal distribution, history and clinical features of AM cases reported to the Atypical Myopathy Alert Group from 2006 to 2009 were described. Comparisons of data from the most severely affected countries and from the large outbreaks were made with Fisher's exact and Welch's tests with Bonferroni correction.
  
  
  RESULTS
  Of 600 suspected cases, 354 met the diagnostic criteria for confirmed or highly probable AM. The largest outbreaks occurred during the autumns of 2006 and 2009 in Belgium, France and Germany. For the first time, donkeys, zebras and old horses were affected, and clinical signs such as gastrointestinal impaction, diarrhoea, penile prolapse, buccal ulceration and renal dysfunction were observed. Affected horses spent >6 h/day on pastures that almost always contained or were surrounded by trees. The latency period was estimated at up to 4 days. Overall survival rate was 26%. Although differences between countries in affected breeds, body condition, horse management and pasture characteristics were recognised, the common presenting clinical signs and mortality were similar between countries.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Epidemiology, Faculty of Veterinary Medicine, University of Liege, Belgium. gaby@equinespecialists.eu
authors.forename: G
authors.initials: G
authors.lastname: van Galen
authors.forename: C
authors.initials: C
authors.lastname: Marcillaud Pitel
authors.forename: C
authors.initials: C
authors.lastname: Saegerman
authors.forename: F
authors.initials: F
authors.lastname: Patarin
authors.forename: H
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authors.lastname: Amory
authors.forename: J D
authors.initials: JD
authors.lastname: Baily
authors.forename: D
authors.initials: D
authors.lastname: Cassart
authors.forename: V
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authors.lastname: Gerber
authors.forename: C
authors.initials: C
authors.lastname: Hahn
authors.forename: P
authors.initials: P
authors.lastname: Harris
authors.forename: J A
authors.initials: JA
authors.lastname: Keen
authors.forename: N
authors.initials: N
authors.lastname: Kirschvink
authors.forename: L
authors.initials: L
authors.lastname: Lefere
authors.forename: B
authors.initials: B
authors.lastname: McGorum
authors.forename: J M V
authors.initials: JM
authors.lastname: Muller
authors.forename: M T J E
authors.initials: MT
authors.lastname: Picavet
authors.forename: R J
authors.initials: RJ
authors.lastname: Piercy
authors.forename: K
authors.initials: K
authors.lastname: Roscher
authors.forename: D
authors.initials: D
authors.lastname: Serteyn
authors.forename: L
authors.initials: L
authors.lastname: Unger
authors.forename: J H
authors.initials: JH
authors.lastname: van der Kolk
authors.forename: G
authors.initials: G
authors.lastname: van Loon
authors.forename: D
authors.initials: D
authors.lastname: Verwilghen
authors.forename: C M
authors.initials: CM
authors.lastname: Westermann
authors.forename: D M
authors.initials: DM
authors.lastname: Votion
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D004196:Disease Outbreaks / Q000662:veterinary*; D004777:Environment; D018397:Equidae; D005060:Europe / Q000453:epidemiology; D009135:Muscular Diseases / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D013997:Time Factors