title: Causes of poor performance of horses during training, racing, or showing: 348 cases (1992-1996).
abstract: OBJECTIVE
  To determine results for horses undergoing a high-speed treadmill examination, including videoendoscopy of the pharynx and larynx before and during exercise, echocardiography before and after exercise, and electrocardiography before, during, and after exercise, because of poor performance.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  348 horses.
  
  
  RESULTS
  A definitive diagnosis was obtained for 256 (73.5%) horses. One hundred forty-eight horses had dynamic obstruction of the airway during exercise, 33 had clinically important cardiac arrhythmias alone, 22 had a combination of dynamic airway obstruction and clinically important cardiac arrhythmias, 19 had poor cardiac fractional shortening immediately after exercise, 10 had exertional rhabdomyolyis, 15 had clinically apparent lameness, and 9 had other disorders. Thirty-nine of the horses with dynamic obstruction of the airway during exercise had multiple airway abnormalities. Fifty-three horses also had subclinical myopathy
  
  
  CONCLUSIONS
  Results suggest that a complete evaluation, including a high-speed treadmill examination, should be conducted in horses with poor performance, regardless or whether horses do or do not have a history of abnormal respiratory noises and particularly if the horses have grade-II or -III left laryngeal hemiplegia.
authors.affiliation: Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square 19348, USA.
authors.forename: B B
authors.initials: BB
authors.lastname: Martin
authors.forename: V B
authors.initials: VB
authors.lastname: Reef
authors.forename: E J
authors.initials: EJ
authors.lastname: Parente
authors.forename: A D
authors.initials: AD
authors.lastname: Sage
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D001193:Arytenoid Cartilage / Q000473:pathology; D009202:Cardiomyopathies / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D003402:Creatine Kinase / Q000097:blood; D004452:Echocardiography / Q000662:veterinary; D004562:Electrocardiography / Q000662:veterinary; D005080:Exercise Test / Q000662:veterinary; D005260:Female; D006337:Heart Murmurs / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006736:Horses; D007794:Lameness, Animal / Q000175:diagnosis / Q000503:physiopathology; D007818:Laryngeal Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D007828:Laryngoscopy / Q000662:veterinary; D008297:Male; D010805:Physical Conditioning, Animal; D012135:Respiratory Sounds / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D012189:Retrospective Studies; D012206:Rhabdomyolysis / Q000175:diagnosis / Q000503:physiopathology / Q000662:veterinary; D014743:Videotape Recording
chemical_list: D003402:Creatine Kinase