68 Pain – an introduction
Almost all pet owners equate pain with a poor quality of life. It is important to recognize the presence of pain in a disease process and to put it into perspective for the owner by discussing definitive and palliative treatment and the duration and severity of pain expected.
The sensation of pain is a subjective interpretation of a noxious stimulus which is transmitted to the cerebral cortex via sensory nerves, dorsal spinal roots, spinal tracts and thalamic nuclei (Fig. 68.1).
The presence of pain in an animal is inferred by the animal’s altered behaviour, posture or gait.
Humans can describe the quality of pain they experience and this gives rise to a lot of jargon.
It is difficult to judge what an animal is experiencing when it scratches, chews, self-mutilates, or twitches the skin. The assumption is that sensation is present but altered and possibly unpleasant. Once a causative lesion has been found in such an animal the human experience of that lesion is assigned, rightly or wrongly, to the animal. This is how we presume animals experience paraesthesias. In this case using jargon can help in finding the correct treatment.