title: Prevalence of mitral valve regurgitation in 79 asymptomatic Norfolk terriers.
abstract: OBJECTIVE
  To determine the prevalence of mitral valve regurgitation (MR) in asymptomatic Swedish Norfolk terriers.
  
  
  METHODS
  Seventy-nine privately owned Norfolk terriers.
  
  
  METHODS
  A prospective observational study was conducted where dogs were recruited via the Swedish Norfolk terrier club. All dogs were examined using the same protocol including physical examination and Doppler echocardiography.
  
  
  RESULTS
  Fifteen dogs (19%) had a murmur at the time of the examination. A total of 35 dogs (44%) had MR, including 23 dogs (29%) with both MR and tricuspid valve regurgitation and 12 dogs (15%) with MR only, identified on Doppler echocardiography. In addition, 7 dogs (9%) had tricuspid valve regurgitation only. The prevalence of MR increased with increasing age (p < 0.0001).
  
  
  CONCLUSIONS
  Mitral valve regurgitation is common in asymptomatic Norfolk terriers with and without murmurs and the prevalence increases with age. The impact of MR in this breed on survival remains to be elucidated by a longitudinal study.
authors.affiliation: Anicura Albano Animal Hospital, Rinkebyvägen 21, 18236, Danderyd, Sweden. Electronic address: anna.bodegard@anicura.se.
authors.forename: A
authors.initials: A
authors.lastname: Bodegård-Westling
authors.affiliation: Anicura Albano Animal Hospital, Rinkebyvägen 21, 18236, Danderyd, Sweden; Department of Clinical Sciences, University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Tidholm
authors.affiliation: Department of Clinical Sciences, University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Häggström
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D005260:Female; D008297:Male; D008944:Mitral Valve Insufficiency / Q000453:epidemiology / Q000662:veterinary*; D010375:Pedigree; D015995:Prevalence; D011446:Prospective Studies; D013548:Sweden / Q000453:epidemiology
keywords: Acquired heart disease; Atrioventricular valve insufficiency; Myxomatous mitral valve disease; Subclinical heart disease