A technique for evaluating analgesia in conscious perching birds

Objective - To develop a technique for objective assessment of modulation of nociperception in conscious perching birds. Animals - 31 adult African grey parrots. Procedure - Birds were randomly assigned to receive saline (0.9% NaCl) solution (n = 10), butorphanol tartrate (11), or buprenorphine hydrochloride (10), IM, Birds were fitted with a surface electrode on the medial metatarsus of 1 leg. An electrical stimulus was delivered to the bird's foot through an aluminum surface on half of the perch. The alternate side of the perch delivered a noxious thermal stimulus. A withdrawal response to either stimulus was recorded when the bird lifted its foot or vigorously flinched its wings. Results - Responses to thermal stimuli were extremely variable during baseline testing and after administration of drugs. Thus, significant differences were not detected after drug injection. In contrast, responses to an electrical stimulus were predictable with much less variation. Conclusions and Clinical Relevance - This method and device allowed for the reliable determination of withdrawal threshold in perching birds. Use of this technique for objective assessment of modulation of nociperception in conscious perching birds will enable assessment of analgesic drugs.