The refinement of husbandry and procedures to reduce animal suffering and improve welfare is an essential component of humane science. Successful refinement depends upon the ability to assess animal welfare effectively, and detect any signs of pain or distress as rapidly as possible, so that any suffering can be alleviated. This document provides practical guidance on setting up and operating effective protocols for the welfare assessment of animals used in research and testing. It sets out general principles for more objective observation of animals, recognizing and assessing indicators of pain or distress and tailoring these to individual projects. Systems for recording indicators, including score sheets, are reviewed and guidance is set out on determining practical monitoring regimes that are more likely to detect any signs of suffering. This guidance is intended for all staff required to assess or monitor animal welfare, including animal technologists and care staff, veterinarians and scientists. It will also be of use to members of ethics or animal care and use committees. A longer version of this document, with further background information and extra topics including training and information sharing, is available on the Laboratory Animals website.

Rat behaviour was studied to develop a reliable method of determining the severity and duration of post-laparotomy pain, and to assess analgesic effects of ketoprofen or carprofen. Behaviour was studied in groups of ten animals 1 h following subcutaneous (s/c) saline (0.2 ml/100 g), ketoprofen or carprofen (5, 10 or 15 mg/kg) given either alone, or prior to surgery. The frequency of over 150 individual behavioural acts was calculated during the first post-treatment hour, the hour immediately prior to darkness, and the first 15 min of each of 5 subsequent hours. Discriminant analysis and analysis of variance isolated several easily recognizable behaviours which were markedly altered in frequency by surgery. These were unaffected by drug administration alone and were mainly transient, easily quantifiable activities; 'cat-like' back arching, horizontal stretching followed by abdominal writhing and twitching while inactive. Reductions in the frequency of these behaviours following surgery with analgesic treatment supported the hypothesis that they reflected post-operative pain. Ketoprofen and carprofen were equipotent and no dose related effects were apparent. Analgesic activity lasted between 4 and 5 h with the 5 mg/kg dosage, this being estimated from the duration of overall and specific behaviour differences between saline and drug treated animals. The data provided substantial evidence as to the usefulness of behavioural criteria for estimating pain severity, and for the first time, the basis of a system for routine pain assessment and management in rats subjected to abdominal surgery.

Buprenorphine has been widely used for post-operative analgesia in laboratory animals. Clinical efficacy has been demonstrated in both subjective and objective pain assessment schemes, however doubts have been expressed as to its value as an analgesic. Initial dosage recommendations were based on analgesiometric studies. It is unlikely, however, that the pain elicited in analgesiometric tests is comparable to post-operative pain. This has resulted in recommendations of excessive dose rates and inappropriate clinical indications. Studies involving tests of the efficacy of buprenorphine for alleviating behavioural or other signs of tonic (post-surgical) pain provide a more appropriate estimation of the analgesic capabilities of the drug. However, buprenorphine also has major effects upon the behaviour of normal (unoperated) animals, and this makes assessments of efficacy difficult with some of the systems used for scoring clinical pain. Nevertheless, our most recent studies of the effects of buprenorphine upon pain-related behaviours in rats support the view that it is an effective post-operative analgesic. This short review critically reappraises the role of buprenorphine in this capacity and discusses a rational approach to the relief of pain in laboratory animals. We conclude that buprenorphine remains a valuable agent for pain relief in a wide range of animal species when used in an appropriate manner.

Prevention of unnecessary pain in laboratory animals requires reliable and practically useful tools for assessing pain severity and analgesic efficacy. We have used a behaviour-based pain scoring system to determine the duration of pain resulting from laparotomy, and the duration of analgesia afforded by orally administered (p.o.) buprenorphine and subcutaneously administered (s.c.) carprofen or buprenorphine in rats. One hour before laparotomy Fisher 344 rats received either saline as a control (0.2 ml/100 g s.c.), carprofen (5 mg/kg s.c.) or buprenorphine (0.05 mg/kg s.c. or 0.4 mg/kg p.o.). The rats were housed singly for 10-min periods of behaviour recording, beginning 30 min after completing surgery. Recording was repeated at three time points every 2 h. The behaviour of controls was distinct from that of the analgesic-treated animals throughout recording; however, the major signs of pain (back-arching, staggering and writhing) were prominent during only the first 270 min in the saline group. This was followed by a period of more subtle differences between the saline- and drug-treated groups. It was concluded that the most acutely painful effects of surgery in this model lasted for between 270 and 390 min, and that this was alleviated throughout its duration by subcutaneously administered carprofen or buprenorphine, and also buprenorphine administered orally. The study demonstrates a clinically relevant and practically useful approach to assessing the duration of post-surgical abdominal pain and analgesic effects in rats.