Sex related differences in analgesia in sheep (Ovis ovis)

Authors: Cook CJ
Publication: New Zealand Veterinary Journal, Volume 45, Issue 4, pp 169-170, Aug 1997
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Anaesthesia/analgesia/sedation, Animal remedies/veterinary medicines, Animal welfare, Behaviour, Endocrine/autocrine/paracrine
Article class: Correspondence

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Abstract: Perception of, and relief from, pain differs markedly between individual animals. In a humane system of animal care, this requires addressing. I have investigated the analgesic effects of different opioid agonists in male and female sheep, and the results suggest a sex-related difference in the efficacy of both kappa and mu opioids. Sheep, Ovis ovis, (six ewes, four rams, four wethers, bodyweights 32-40 kg) were grazed in sex-separated flocks. Each individual was restrained for a period of 60 minutes within the laboratory and subjected to two thermal stimuli, the first 20 and the second 40 minutes after start of restraint. Thermal stimuli were delivered by a small probe (0.25 mm²) heated to 47°C to the side of the nose and the withdrawal time of the nose from the source was recorded (the animal`s head was able to move freely). If withdrawl did not occur within 10 seconds the probe was withdrawn. Electrocardiograms were…

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