The controversial distinction between stress, a natural and often useful quality, and distress, an unpleasant and harmful one, is the subject of an article in Science for November 24. Critics of animal research methods have asked when stress in an animal becomes unwarranted distress and therefore cruelty.
Stress is defined as a demand on physical or mental energy created by a situation. Distress, by contrast, is severe pressure of pain or sorrow, or anguish. The United States government is now attempting to clarify the question arising from the need to care for millions of animals at present being used in scientific research. A deep rift has appeared between animal activists on the one hand, who interpret proposed new regulations as a welcome move towards eliminating all painful procedures, and the majority of research workers who are insisting that the present system of regulation is working well and calls for no further changes, at least major ones.
The US Department of Agriculture is attempting to assess the need to form and adopt a formal definition of "distress"which is called for in the provisions of the Animal Welfare Act. Emphasis has been placed on the infliction of pain, and has taken little account of the lesser condition of distress. The working definition of distress at present accepted provisionally is "a state in which an animal cannot escape from or adapt to the internal or external stressors or conditions it experiences, resulting in negative effects on its wellbeing". Public comments on such a definition have been invited, and some 2,600 pieces of advice and criticism have been submitted.
The reporting system used by research institutes at present recognises three categories: animals which are not subjected to painful procedures, those which are likely to experience pain at some time and are therefore given analgesics and those which cannot be given analgesia since it would render a study inconclusive. This last category includes rodents and other animals used in drug testing. One problem is that the data ignore the intensity or duration of the pain, the effectiveness of available measures to overcome it, including palliative methods.
The definition of what is meant by distress is being questioned, since there are no simple physiological or behavioural criteria by which it may be judged, and there is no way of drawing a satisfactory division between what constitutes stress and distress in an animal. In face of the insistence by animal welfare organisations that in testing procedures pain and distress must be eliminated if they are to be acceptable, attempts are being made to specify the behavioural signs that can reliably be interpreted as indicating distress. Argument over the issue is expected to become more intense over the next few years.