Om smärta hos försöksdjur

Abstract

On Pain in Laboratory Animals. The article gives a short discription in Swedish on the subject ofpain in animals based upon some recent litterature. Suffering, which is the word used in Swedish legislation, and pain, are concepts which are both very difficult to define. Pain is a perception with sensory as well as affective dimensions and this renders knowledge about pain in animals indirect through analogies between humans and animals in anatomy, physiology and behaviour. An important point is made of the fact that pain is not equivalent with nociception. Pain, being a perception, is dependant upon the animal’s conscious state, i.e. on a functioning cerebral cortex (at least in higher animals and man), while different aspects of nociception, >>pain reflexes<<, might occur without pain in true sense, as under anesthesia. After defining some concepts in the area of pain, the neurophysiological mechanisms are shortly described. Peripheral and central painregulating systems are discussed and it is pointed out that pain detection threshold as well as pain sensitivity range are parameters that could be quite variable and regulated through central nervous mechanisms. In the sections on assessment of pain and suffering it is stressed that it is the responsibility ofthe researcher both to be aware of and to able to recognize signs of pain or distress in his/her animals. It is also important to consider degrees of pain, from trivial over moderate to severe pain. The severe pain of extensive surgery or soft tissue damage is in practice not the big problems, but instead the broad field of moderate pain, which might be difficult to recognize for people less experienced in the particular normal behaviour of a certain animal species. In such cases it is suggested that pain killers should be used much more than is done today. There is the striking both similarity and contrast in the fact that antibiotics are often used >>for safety<< even if an infection is not verified, but pain killers are seldom used, unless very clear signs of pain or distress are evident. In cases of more chronic types of pain or suffering there is need for good knowledge and experience of the normal range of behaviour of the particular animal species concerned, because the potential suffering of the animal is judged mainly from changes in its behavioural repertoire. If animals are suspected to suffer in any way, possible causes must be seeked and preferably removed. Otherwise treatment with analgetics or sedatives must be instituted, if the experiment does not prevent it, or one must seriously consider euthanasia. This is in some instances the only proper way to handle suffering in laboratory animals, also because obviously suffering animals are by all decent standards not even scientifically valuable.