Evaluation of thermal antinociceptive effects after oral administration of tramadol hydrochloride to American kestrels (Falco sparverius).
OBJECTIVE
To evaluate the thermal antinociceptive and sedative effects and duration of action of tramadol hydrochloride after oral administration to American kestrels (Falco sparverius).


METHODS
12 healthy 3-year-old American kestrels.


METHODS
Tramadol (5, 15, and 30 mg/kg) and a control suspension were administered orally in a masked randomized crossover experimental design. Foot withdrawal response to a thermal stimulus was determined 1 hour before (baseline) and 0.5, 1.5, 3, 6, and 9 hours after treatment. Agitation-sedation scores were determined 3 to 5 minutes before each thermal stimulus test.


RESULTS
The lowest dose of tramadol evaluated (5 mg/kg) significantly increased the thermal foot withdrawal thresholds for up to 1.5 hours after administration, compared with control treatment values, and for up to 9 hours after administration, compared with baseline values. Tramadol at doses of 15 and 30 mg/kg significantly increased thermal thresholds at 0.5 hours after administration, compared with control treatment values, and up to 3 hours after administration, compared with baseline values. No significant differences in agitation-sedation scores were detected between tramadol and control treatments.


CONCLUSIONS
Results indicated oral administration of 5 mg of tramadol/kg significantly increased thermal nociception thresholds for kestrels for 1.5 hours, compared with a control treatment, and 9 hours, compared with baseline values; higher doses resulted in less pronounced antinociceptive effects. Additional studies with other types of stimulation, formulations, dosages, routes of administration, and testing times would be needed to fully evaluate the analgesic and adverse effects of tramadol in kestrels and other avian species.
Veterinary Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.
David Sanchez-Migallon
DS
Guzman
Tracy L
TL
Drazenovich
Glenn H
GH
Olsen
Neil H
NH
Willits
Joanne R
JR
Paul-Murphy
D000284:Administration, Oral; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D018592:Cross-Over Studies; D046093:Falconiformes / Q000502:physiology*; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010146:Pain / Q000517:prevention & control / Q000662:veterinary*; D014147:Tramadol / Q000008:administration & dosage / Q000494:pharmacology*
D000701:Analgesics, Opioid; D006993:Hypnotics and Sedatives; D014147:Tramadol