Background: Some environmental factors lead to physiological and behavioral changes in laboratory animals.
Methods: Twenty male mice and twenty handlers were used in this study. The handlers were given three minutes to pick up and handle a mouse from his cage. Handlers were divided into two groups based on their scores when handling mice: low- and high score groups. For two weeks, each mouse was handled every other day. Mice''s behavioral reactions to handling, such as hyperactivity, escape, and elimination, were observed. After each handling, mice were placed in a light-dark box (LDB) to examine their anxiety-like behavior, and at the end of the experiment, they were placed in an elevated plus maze (EPM).
Results and conclusion: In contrast to high handling scores, the results showed that low handling scores increased the mice''s hyperactivity, escape, and elimination responses; they also increased the latency of mouse to move from dark to light compartments in the LDB; and they decreased the number of entries and the amount of time spent in the open arms during the EPM test. It is concluded that the prolonged handling of mice during ordinary work had a negative impact on the health of the mice and enhanced their fearful and stressful responses.