title: The prevalence of laryngeal disease in a large population of competition draft horses.
abstract: OBJECTIVE
  (1) To determine the effect of age, height, weight, breed, sex, and specific use on the prevalence of idiopathic left laryngeal hemiplegia (ILH) in a population of draft performance horses; (2) to determine the association between tracheal mucus and laryngeal dysfunction, and the prevalence of exercise-induced pulmonary hemorrhage (EIPH) in a population of draft performance horses.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Draft horses competing at the 2005 Michigan Great Lakes Draft Horse Show.
  
  
  METHODS
  Endoscopic examinations were performed on horses competing at the 2005 Michigan Great Lakes Draft Horse Show. Signalment, height, and weight were obtained from the owners and trainers.
  
  
  RESULTS
  Belgian, Percheron, and Clydesdale horses (n=183) were studied. Prevalence of ILH was 35%. Horse height was significantly associated with the risk of ILH in Belgian and Percheron horses but not Clydesdales. There was a significantly different prevalence of ILH among the breeds such that 42% Belgians, 31% Percherons, and 17% Clydesdales were affected. Laryngeal disease was a risk factor for increased tracheal mucus. None of the horses had acute evidence of EIPH.
  
  
  CONCLUSIONS
  The prevalence of ILH in draft horses has increased or is higher in competition horses compared with previously studied groups. Tracheal and/or pulmonary inflammation may be more common in draft horses with ILH based on our findings that horses with ILH have more tracheal mucus than horses with normal laryngeal function.
  
  
  CONCLUSIONS
  Selection pressure for large, taller, longer-necked horses may be responsible for a seemingly increased incidence of ILH in competitive draft horses.
authors.affiliation: Department of Large Animal Clinical Sciences and Small Animal Clinical Sciences, Michigan State University, East Lansing, 48824, USA. brakenho@cvm.msu.edu
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Brakenhoff
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Holcombe
authors.forename: Joe G
authors.initials: JG
authors.lastname: Hauptman
authors.forename: Holly K
authors.initials: HK
authors.lastname: Smith
authors.forename: Frank A
authors.initials: FA
authors.lastname: Nickels
authors.forename: John P
authors.initials: JP
authors.lastname: Caron
mesh_terms: D000818:Animals; D001947:Breeding; D003430:Cross-Sectional Studies; D016145:Endoscopy, Digestive System / Q000379:methods / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D006736:Horses; D007249:Inflammation / Q000453:epidemiology / Q000235:genetics / Q000473:pathology / Q000662:veterinary; D007818:Laryngeal Diseases / Q000453:epidemiology / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D008297:Male; D008824:Michigan; D009093:Mucus / Q000378:metabolism*; D015995:Prevalence; D012307:Risk Factors; D012641:Selection, Genetic