Among a large number of mice exposed to the combined nesting material or to the fiber material alone, we observed 13 cases of mice, both neonates and adults, becoming caught in nesting material. As a result of entanglement, these mice suffered injuries that were severe enough to warrant immediate euthanasia. In 12 cases, we observed that fiber nesting material was wrapped rigidly around the limbs, severing the blood flow and causing mild (Fig. 1) to severe cases of reactive edema and necrosis. In one case, we observed shredded paper material wound tightly around a mouse's abdomen. Although the number of affected animals was small, in modern-day laboratory animal housing it is our responsibility to prevent suffering in all animals as far as possible.

The Laboratory Mouse (HANDBOOK OF EXPERIMENTAL ANIMALS) Hans Hedrich

 d0d94e66b7