Abstract
Questionnaires on research activities, mortality rates observed in various age groups, extent of examination of dead hamsters, and natural disease conditions and their relative importance were returned by 24 of 43 organisations surveyed in the United States. The average preweaning mortality rate due to all causes was 11·9%. Comparative data from 6 organisations that raised 87880 hamsters in the calendar year 1971 indicated that 97·5% of total preweaning mortality was due to cannibalism. 13·7% of all animals died before use for experiments. 'Wet-tail' was the most frequently recognized disease (71%), and it was also listed as the most important. Pneumonia was recognized by 43% of the respondents and was most commonly listed as second in importance. A selective review of the literature is presented on those diseases recognized by more than one survey respondent.