title: Thermal threshold testing for evaluation of analgesics in New Zealand white rabbits.
abstract: We adapted a thermal analgesiometric device developed for cats for use in unrestrained rabbits. A probe composed of an electrical element and temperature sensor was held against shaved skin by using an elasticized band placed circumferentially around the thorax. An inflated bladder located between the probe and elastic maintained constant contact between probe and skin. The probe was heated until the rabbit displayed a behavioral reaction or the safety cutoff of 55 °C was reached. Threshold temperatures in unmedicated rabbits were stable over a 5-h period provided that tests were 15 min or more apart. Careful acclimation and testing resulted in no false-negative responses, and sham testing did not produce false-positive results. When compared with baseline values, thermal thresholds were significantly increased from 30 to 240 min, but not 300 min, after the administration of morphine at 3 mg/kg. Administration of equivalent volumes of saline via the same route had no effect on thermal threshold. This device may be suitable for investigating analgesic pharmacology in rabbits.
authors.affiliation: School of Veterinary Medicine, University of California, Davis, California, USA. lsbarter@ucdavis.edu
authors.forename: Linda S
authors.initials: LS
authors.lastname: Barter
authors.forename: Anna
authors.initials: A
authors.lastname: Kwiatkowski
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005260:Female; D006358:Hot Temperature; D009020:Morphine / Q000494:pharmacology; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D011817:Rabbits; D012684:Sensory Thresholds / Q000187:drug effects / Q000502:physiology; D013697:Thermosensing
chemical_list: D000700:Analgesics; D009020:Morphine
references.citation: Lab Anim. 1984 Apr;18(2):147-60
references.pmid: 6146743
references.citation: Somatosens Res. 1983;1(2):119-29
references.pmid: 6679916
references.citation: J Vet Pharmacol Ther. 2006 Dec;29(6):531-7
references.pmid: 17083457
references.citation: Am J Vet Res. 2007 Jul;68(7):699-703
references.pmid: 17605603
references.citation: Res Vet Sci. 2002 Jun;72(3):205-10
references.pmid: 12076115
references.citation: J Vet Intern Med. 2004 Mar-Apr;18(2):190-5
references.pmid: 15058769
references.citation: Vet Rec. 2003 Oct 11;153(15):462-5
references.pmid: 14584576
references.citation: Lab Anim. 1988 Jul;22(3):217-22
references.pmid: 3172701
references.citation: Am J Vet Res. 2004 Aug;65(8):1085-9
references.pmid: 15334842
references.citation: J Feline Med Surg. 2009 Feb;11(2):76-81
references.pmid: 18675572