A Simple and Inexpensive Device for Restraining Rodents. ∗

Abstract

In many experimental procedures involving rats or mice, regularly timed blood specimens must be obtained. The use of the tail veins as a source of this blood necessitates incapacitating the animal in either elaborate restraining devices or wrapping them in toweling. Both techniques are often traumatic to both animal and experimenter. A simple device is described which alleviates this problem.

An ordinary low-density narrow-mouth polyethylene bottle is cut with a razor blade as in Fig. 1. Enough of the bottle is left intact to allow the rat to brace his hind legs. Also an injection port may be cut in the side if necessary. The animal needs very little inducement to enter the bottle and frequently will walk in to it of its own accord if the bottle is merely placed before it. Once the rat is in with its tail still out, a wide piece of adhesive tape is used to close the entrance. The size of the bottle should be commensurate with the size of the rat; an 8 oz bottle will conveniently hold a 200 g rat.

Once within the bottle, the rat cannot turn around, sits comfortably with his nose in the neck of the bottle thus breathing freely, and is handled easily without being agitated or aroused, Intraperitioneal injections can be given easily through a port cut in the side of the bottle. If the experiment is terminal, the bottle cap, containing a piece of cotton saturated with chloroform, my be screwed on, to kill the animal. The device is sufficiently inexpensive so that both rat and bottle may be disposed.