title: Evaluation of thermal antinociceptive effects after intramuscular administration of hydromorphone hydrochloride to American kestrels (Falco sparverius).
abstract: OBJECTIVE
  To evaluate the antinociceptive and sedative effects and duration of action of hydromorphone hydrochloride after IM administration to American kestrels (Falco sparverius).
  
  
  METHODS
  11 healthy 2-year-old American kestrels.
  
  
  METHODS
  Hydromorphone (0.1, 0.3, and 0.6 mg/kg) and an equivalent volume of saline (0.9% NaCl) solution (control treatment) were administered IM to kestrels in a masked randomized complete crossover study design. Foot withdrawal response to a thermal stimulus was determined 30 to 60 minutes before (baseline) and 0.5, 1.5, 3, and 6 hours after treatment administration. Agitation-sedation scores were determined 3 to 5 minutes before each thermal test.
  
  
  RESULTS
  Hydromorphone at 0.6 mg/kg, IM, significantly increased the thermal foot withdrawal threshold, compared with the response after administration of saline solution, for up to 3 hours, and hydromorphone at 0.1, 0.3, and 0.6 mg/kg, IM, significantly increased withdrawal responses for up to 6 hours, compared with baseline values. No significant differences in mean sedation-agitation scores were detected between hydromorphone and saline solution treatments; however, appreciable sedation was detected in 4 birds when administered 0.6 mg of hydromorphone/kg.
  
  
  CONCLUSIONS
  Hydromorphone at the doses evaluated significantly increased the thermal nociception threshold for American kestrels for 3 to 6 hours. Additional studies with other types of stimulation, formulations, dosages, routes of administration, and testing times are needed to fully evaluate the analgesic and adverse effects of hydromorphone in kestrels and other avian species and the use of hydromorphone in clinical settings.
authors.affiliation: Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA. guzman@ucdavis.edu
authors.forename: David Sanchez-Migallon
authors.initials: DS
authors.lastname: Guzman
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Drazenovich
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 / Q000494:pharmacology; D000818:Animals; D001715:Bird Diseases / Q000188:drug therapy* / Q000209:etiology; D018592:Cross-Over Studies; D046093:Falconiformes; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D004091:Hydromorphone / Q000008:administration & dosage / Q000494:pharmacology*; D007273:Injections, Intramuscular; D008297:Male; D010146:Pain / Q000517:prevention & control*
chemical_list: D000701:Analgesics, Opioid; D004091:Hydromorphone