title: Changes in gallbladder volume in healthy dogs after food was withheld for 12 hours followed by ingestion of a meal or a meal containing erythromycin.
abstract: OBJECTIVE
  To assess the influence of meal ingestion and orally administered erythromycin on gallbladder volume in dogs.
  
  
  METHODS
  22 healthy dogs.
  
  
  METHODS
  Ultrasonographically determined gallbladder dimensions in unsedated dogs were used to calculate volume. Measurements were recorded after food was withheld for 12 hours (time 0) and 15, 30, 45, 60, 90, and 120 minutes after a 100-g meal without (n = 22) or with erythromycin (1.0 mg/kg [7], 2.5 mg/kg [7], and both dosages [8]). Gallbladder ejection fraction represented the percentage of volume change from time 0. Intraday and interday coefficients of variation determined operator repeatability and physiologic variation.
  
  
  RESULTS
  We did not detect significant differences in gallbladder volume per unit of body weight between treatments at time 0 or in ejection fraction percentage within or between treatments. Median time 0 gallbladder volume was 0.6 mL/kg (range, 0.4 to 1.9) but was > 1.0 mL/kg in 3 of 22 (14%) dogs and <or= 1.0 mL/kg in 19 of 22 (86%) dogs. Twenty dogs achieved an ejection fraction >or= 25% with at least 1 treatment, but 2 dogs with a gallbladder volume <or= 1.0 mL/kg at time 0 did not. Intraday and interday coefficients of variation were 18% and 25%, respectively.
  
  
  CONCLUSIONS
  Gallbladder volume <or= 1.0 mL/kg at time 0 and ejection fraction >or= 25% were typical. No treatment consistently induced greater gallbladder contraction. Dogs with a gallbladder volume > 1.0 mL/kg and ejection fraction < 25% may require a combined meal and erythromycin protocol.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Keri L
authors.initials: KL
authors.lastname: Ramstedt
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Center
authors.forename: John F
authors.initials: JF
authors.lastname: Randolph
authors.forename: Amy E
authors.initials: AE
authors.lastname: Yeager
authors.forename: Hollis N
authors.initials: HN
authors.lastname: Erb
authors.forename: Karen L
authors.initials: KL
authors.lastname: Warner
mesh_terms: D000818:Animals; D004285:Dogs / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D004917:Erythromycin / Q000008:administration & dosage*; D005215:Fasting; D005260:Female; D005704:Gallbladder / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D008297:Male; D009037:Motilin / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D018709:Statistics, Nonparametric; D014463:Ultrasonography
chemical_list: D005765:Gastrointestinal Agents; D009037:Motilin; D004917:Erythromycin