title: Idiopathic muscular hypertrophy of the oesophagus in the horse: a retrospective study of 31 cases.
abstract: BACKGROUND
  To present the first report of a case series concerning equine idiopathic muscular hypertrophy of the oesophagus (IMHO).
  
  
  OBJECTIVE
  To investigate the clinical and pathological features of the disorder.
  
  
  METHODS
  The medical records of 31 horses suffering from the disorder were reviewed retrospectively. In all these animals the diagnosis was confirmed at post mortem examination.
  
  
  RESULTS
  The median age of the affected horses was 12.5 +/- 5.6 years (range 1-26) without sex or breed predilection. Only 2 out of 31 horses showed clinical signs associated with oesophageal dysfunction, indicating that the muscular hypertrophy was rather a coincidental post mortem finding. Histology revealed thickening of the distal portion of the oesophagus mainly involving the circular layer of the tunica muscularis without fibrosis or inflammation. In 8 cases, the disorder was seen in concurrence with idiopathic hypertrophy of the tunica muscularis of various other parts of the gastrointestinal tract.
  
  
  CONCLUSIONS
  In the majority of patients, IMHO was a coincidental finding at post mortem examination usually confined to the smooth, circular muscle layer of the tunica muscularis externa.
  
  
  CONCLUSIONS
  Further research is necessary to study the precise effect of IMHO on oesophageal function.
authors.affiliation: Department of Equine Sciences, Medicine Section, Faculty of Veterinary Medicine, Utrecht University, PO Box 80.152, 3508 TD Utrecht, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: Benders
authors.forename: E J B
authors.initials: EJ
authors.lastname: Veldhuis Kroeze
authors.forename: J H
authors.initials: JH
authors.lastname: van der Kolk
mesh_terms: D000818:Animals; D004935:Esophageal Diseases / Q000473:pathology / Q000662:veterinary*; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D006984:Hypertrophy / Q000473:pathology / Q000662:veterinary; D008297:Male; D009130:Muscle, Smooth / Q000473:pathology*; D012189:Retrospective Studies