Mortality, body weight, food and water consumption, and clinical signs in Slc: B6C3F1 (C57BL/6 x C3H) mice utilized in chronic toxicity and carcinogenicity studies.

In vivo historical control data for Slc: B6C3F1 mice, including mortality, body weight, food and water consumption, and clinical signs and which were obtained from long-term toxicity and carcinogenicity studies (11 male and 12 female studies) conducted at the Biosafety Research Center, Foods, Drugs and Pesticides, (An-Pyo Center) during the last five years are presented. Mean survival at 83 and 109 weeks of age was 96.4% (min: 94.0%, max: 100%) and 79.0% (min: 74.0%, max: 86.0%) in males and 98.7% (min: 96.0%, max: 100%) and 81.7% (min: 70.0%, max: 90.0%) in females, respectively. The maximum mean body weight of males and females was 45.1 +/- 3.1 g (mean +/- S.D.) and 39.2 +/- 4.1 g, respectively. Male mice attained their maximum body weight at 72.7 +/- 4.3 weeks of age and females at 76.2 +/- 5.9 weeks of age. Clinical symptoms increased with age, particularly after week 84, and included: wasting, piloerection and palpable abdominal masses. Hypothermia and auricular pallor were common findings in moribund animals from week 79 to 104 of the studies. The use of in-house, historical control data can prove invaluable in the evaluation and interpretation of experimental results, especially in long-term and life-time studies.