Monitoring animal health during chronic toxicity studies

Adequate and appropriate appraisal of the health of the animals in toxicity studies is required to differentiate between toxic manifestations attributable to the test material and non-treatment-related disease. The appraisal will help to ensure that each animal remains on test for as long as reasonably possible and that useful tissue samples are obtained from each animal. Attainment of this objective requires highly motivated personnel who have undergone a specific and continuous training program. The establishment of protocols and procedures for daily and weekly monitoring of the animals, and an efficient and relevant system for data collection, recording, and storage is also required. Various laboratory and clinical procedures are described which may be used either on a routine basis or as diagnostic tools. By following the described procedures it has been possible to reduce the loss of animal tissues due to autolysis to less than 1% during chronic feeding studies.