Current practices of pain assessment and analgesic use in laboratory mice: A 2022 FELASA Working Group survey

Assessing and alleviating pain in animals involved in research is critically important. However, the effective implementation of pain management depends on the knowledge and attitudes of the personnel involved. Following a Federation of European Laboratory Animal Science Associations 'Pain in Mice' working group initiative, a questionnaire to survey current practices concerning analgesic use in laboratory mice was distributed to several professional groups in the field of laboratory animal science. Besides demographic data, attitudes to pain and analgesia and sources of information and advice on pain management were assessed. Data were gathered and analysed through an e-survey provider. Most respondents (<i>N</i> = 222) were from Europe (90%). Analgesics were administered to murine surgical models by 92% of respondents in most cases and by 66% to all mice undergoing surgery. Most respondents used multimodal analgesic regimens (69%). For non-surgical models, 34% of respondents provided analgesics. The most commonly administered classes of analgesics were opioids (mostly buprenorphine) and non-steroidal anti-inflammatory drugs (mostly meloxicam and carprofen). A wide range of dose rates of meloxicam and carprofen was reported. Local anaesthetics were also widely used in surgical models (mostly lidocaine). Pain assessment was undertaken by most respondents (98%). In conclusion, most respondents provided analgesics to mice undergoing surgery and used analgesics in some non-surgical models. A considerable variation in the dose range used and the timing of administration of analgesics likely reflects both a lack of data and variation in pain assessment methodologies.