title: The effect of body condition on propofol requirement in dogs.
abstract: OBJECTIVE
  To determine if body condition score (BCS) influences the sedative effect of intramuscular (IM) premedication or the dose of intravenous (IV) propofol required to achieve endotracheal intubation in dogs.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  Forty-six client-owned dogs undergoing general anaesthesia.
  
  
  METHODS
  Dogs were allocated to groups according to their BCS (BCS, 1 [emaciated] to 9 [obese]): Normal-weight Group (NG, n = 25) if BCS 4-5 or Over-weight Group (OG, n = 21) if BCS over 6. Dogs were scored for sedation prior to IM injection of medetomidine (5 μg kg(-1) ) and butorphanol (0.2 mg kg(-1) ) and twenty minutes later anaesthesia was induced by a slow infusion of propofol at 1.5 mg kg(-1)  minute(-1) until endotracheal intubation could be achieved. The total dose of propofol administered was recorded. Data were tested for normality then analyzed using Student t-tests, Mann-Whitney U tests, chi-square tests or linear regression as appropriate.
  
  
  RESULTS
  Mean ( ± SD) propofol requirement in NG was 2.24 ± 0.53 mg kg(-1) and in OG was 1.83 ± 0.36 mg kg(-1) . The difference between the groups was statistically significant (p = 0.005). The degree of sedation was not different between the groups (p = 0.7). Post-induction apnoea occurred in 11 of 25 animals in the NG and three of 21 in OG (p = 0.052).
  
  
  CONCLUSIONS
  Overweight dogs required a lower IV propofol dose per kg of total body mass to allow tracheal intubation than did normal body condition score animals suggesting that IV anaesthetic doses should be calculated according to lean body mass. The lower dose per kg of total body mass may have resulted in less post-induction apnoea in overweight/obese dogs. The effect of IM premedication was not significantly affected by the BCS.
  
  
  CONCLUSIONS
  Induction of general anaesthesia with propofol in overweight dogs may be expected at lower doses than normal-weight animals.
authors.affiliation: Department of Clinical Veterinary Medicine, University of Cambridge, Cambridge, UK. sb889@cam.ac.uk
authors.forename: Sarah
authors.initials: S
authors.lastname: Boveri
authors.forename: Jacqueline C
authors.initials: JC
authors.lastname: Brearley
authors.forename: Alexandra H A
authors.initials: AH
authors.lastname: Dugdale
mesh_terms: D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D050177:Overweight / Q000378:metabolism / Q000662:veterinary*; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D018686:Anesthetics, Intravenous; D015742:Propofol
keywords: dog; obesity; propofol