title: Urodynamic and morphometric characteristics of the lower urogenital tracts of female Beagle littermates during the sexually immature period and first and second estrous cycles.
abstract: OBJECTIVE
  To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods.
  
  
  METHODS
  5 female Beagle littermates.
  
  
  METHODS
  Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles.
  
  
  RESULTS
  At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus.
  
  
  CONCLUSIONS
  Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.
authors.affiliation: Department of Companion Animal Clinical Sciences, College of Veterinary Medicine, University of Liège, 4000 Liège, Belgium.
authors.forename: Stéphanie M
authors.initials: SM
authors.lastname: Noël
authors.forename: Frédéric
authors.initials: F
authors.lastname: Farnir
authors.forename: Annick J
authors.initials: AJ
authors.lastname: Hamaide
mesh_terms: D000818:Animals; D004285:Dogs / Q000033:anatomy & histology* / Q000502:physiology*; D030762:Estrous Cycle; D005260:Female; D011312:Pressure; D012741:Sexual Maturation; D014563:Urodynamics; D014566:Urogenital System / Q000033:anatomy & histology* / Q000502:physiology*