title: Effects of butorphanol on the minimum anesthetic concentration for sevoflurane in guineafowl (Numida meleagris).
abstract: OBJECTIVE
  To determine the minimum anesthetic concentration (MAC) for sevoflurane and measure the dose and temporal effects of butorphanol on the MAC for sevoflurane in guineafowl.
  
  
  METHODS
  10 healthy adult guineafowl (Numida meleagris).
  
  
  METHODS
  Each bird was anesthetized with sevoflurane, and a standard bracketing method was used to measure the MAC in response to a noxious electrical stimulus. Subsequently, conditions were adjusted so that each bird was anesthetized with sevoflurane at a fraction of its respective MAC (eg, 0.7 times the MAC for that bird). Butorphanol tartrate (2 mg/kg, IV) was administered, and a noxious stimulus was applied every 15 minutes until the bird moved in response. The reduction in MAC was estimated with logistic regression by use of a standard quantal method. After an interval of ≥ 1 week, the MAC reduction experiment was repeated with an increased butorphanol dosage (4 mg/kg).
  
  
  RESULTS
  Individual mean ± SE MAC for sevoflurane was 2.9 ± 0.1%. At 15 minutes after administration of 2 mg of butorphanol/kg, estimated reduction in the MAC for sevoflurane was 9 ± 3%. At 15 and 30 minutes after administration of 4 mg of butorphanol/kg, estimated reduction in the MAC for sevoflurane was 21 ± 4% and 11 ± 8%, respectively.
  
  
  CONCLUSIONS
  In guineafowl, the MAC for sevoflurane was similar to values reported for other species. Increasing the butorphanol dosage decreased the MAC for sevoflurane, but the effect was small and of short duration for dosages up to 4 mg/kg.
authors.affiliation: Department of Veterinary Clinics and Surgery, Faculdade de Ciências Agrárias e Veterinárias, São Paulo State University, Jaboticabal, Brazil. aescobarvet@yahoo.com.br
authors.forename: André
authors.initials: A
authors.lastname: Escobar
authors.forename: Carlos A A
authors.initials: CA
authors.lastname: Valadão
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Brosnan
authors.forename: Anna C
authors.initials: AC
authors.lastname: Denicol
authors.forename: Fabíola N
authors.initials: FN
authors.lastname: Flôres
authors.forename: Roberto
authors.initials: R
authors.lastname: Thiesen
authors.forename: Cássia M M
authors.initials: CM
authors.lastname: Coelho
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000769:Anesthesia, Inhalation / Q000662:veterinary*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D002077:Butorphanol / Q000008:administration & dosage* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D046094:Galliformes; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage* / Q000494:pharmacology*; D000077149:Sevoflurane
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D002077:Butorphanol