title: Evaluation of thermal antinociceptive effects and pharmacokinetics after intramuscular administration of butorphanol tartrate to American kestrels (Falco sparverius).
abstract: OBJECTIVE
  To evaluate antinociceptive effects and pharmacokinetics of butorphanol tartrate after IM administration to American kestrels (Falco sparverius).
  
  
  METHODS
  Fifteen 2- to 3-year-old American kestrels (6 males and 9 females).
  
  
  METHODS
  Butorphanol (1, 3, and 6 mg/kg) and saline (0.9% NaCl) solution were administered IM to birds in a crossover experimental design. Agitation-sedation scores and foot withdrawal response to a thermal stimulus were determined 30 to 60 minutes before (baseline) and 0.5, 1.5, 3, and 6 hours after treatment. For the pharmacokinetic analysis, butorphanol (6 mg/kg, IM) was administered in the pectoral muscles of each of 12 birds.
  
  
  RESULTS
  In male kestrels, butorphanol did not significantly increase thermal thresholds for foot withdrawal, compared with results for saline solution administration. However, at 1.5 hours after administration of 6 mg of butorphanol/kg, the thermal threshold was significantly decreased, compared with the baseline value. Foot withdrawal threshold for female kestrels after butorphanol administration did not differ significantly from that after saline solution administration. However, compared with the baseline value, withdrawal threshold was significantly increased for 1 mg/kg at 0.5 and 6 hours, 3 mg/kg at 6 hours, and 6 mg/kg at 3 hours. There were no significant differences in mean sedation-agitation scores, except for males at 1.5 hours after administration of 6 mg/kg.
  
  
  CONCLUSIONS
  Butorphanol did not cause thermal antinociception suggestive of analgesia in American kestrels. Sex-dependent responses were identified. Further studies are needed to evaluate the analgesic effects of butorphanol in raptors.
authors.affiliation: Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616.
authors.forename: David Sanchez-Migallon
authors.initials: DS
authors.lastname: Guzman
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Drazenovich
authors.forename: Butch
authors.initials: B
authors.lastname: KuKanich
authors.forename: Glenn H
authors.initials: GH
authors.lastname: Olsen
authors.forename: Neil H
authors.initials: NH
authors.lastname: Willits
authors.forename: Joanne R
authors.initials: JR
authors.lastname: Paul-Murphy
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000818:Animals; D002077:Butorphanol / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D016292:Procedural Sedation / Q000379:methods / Q000662:veterinary; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D059226:Nociceptive Pain / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D010147:Pain Measurement / Q000379:methods / Q000662:veterinary; D020304:Raptors / Q000502:physiology*; D012727:Sex Characteristics
chemical_list: D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D002077:Butorphanol