The assessment of nociceptive and non-nociceptive skin sensitivity in the Japanese quail (Coturnix japonica)

We evaluated the efficacy of two nociceptive tests, the hot water (HWT) and the foot pressure tests (FPT), and one non-nociceptive test (Semmes-Weinstein test, SWT) in assessing skin sensitivity in conscious Japanese quail. All stimuli elicited a reflex-like, strongly reproducible response. Responses in the HWT and FPT were identified as typical nocifensive flight-fight behavior. In untreated birds, these responses occurred at temperatures and forces described previously as noxious. In the SWT, two responses were observed: a slight ruffling of the cloacal gland feathers due to the stimulation of the cloacal gland, and a brief extension of the limbs due to the stimulation of the ilium or pectoral apterium. These reactions occurred at intensities recognized as innocuous. Morphine significantly altered the response latency and threshold in the HWT and FPT, but had no effect in the SWT. However, the SWT response threshold was significantly increased by local application of xylocaine. Taken together, the pattern of the responses, the intensities and the effects of morphine and xylocaine allowed to distinguish between nociceptive and non-nociceptive tests. They also demonstrate the efficacy of these tests to evaluate skin sensitivity in quail and to assess its modulation by chemical factors that affect somatosensory processes. (C) 2002 Elsevier Science B.V. All rights reserved.