Performance of severity parameters to detect chemotherapy-induced pain and distress in mice

According to European Union directive 2010/63/EU a severity classification of experimental procedures performed on laboratory animals is mandatory. This includes a prospective evaluation of all interventions performed within the experiment, as well as an assessment of the actual burden of each animal during the experiment. In this regard, the evaluation and scoring of defined criteria regarding the health state of animals could help to early identify deteriorations in animal health and facilitate the application of humane endpoints. This article discusses the applicability of an adapted score sheet in BALB/cAnNRj mice receiving either cisplatin, doxorubicin or busulfan, three chemotherapeutic agents with different toxicological profiles and longitudinal non-invasive molecular imaging. The health state was investigated by score sheets documenting general state, body weight, spontaneous behaviour and treatment specific parameters (e.g. anaemia, neurotoxicity, persistent diarrhoea). Although blood and serum analyses clearly indicated various organ damage, most scoring parameters except for body weight did not report on the deceasing animal health state. Thus, there is need for more sensitive observational parameters to judge the animal's health state and welfare.