Handling and restraining procedures vary depending on animal’s species, size, age, strain and temperament (Machholz, Mulder, Ruiz, Corning, & Pritchett-Corning., 2012). However, all the procedures have a common underlying principle that they should not cause pain, stress, or discomfort to the animal.
One-handed manual restraining technique for mice consists of following steps:
Noise or disturbance in the laboratory room could disturb the animal behavior which could alter experimental findings and associated behavior. The animal is safely taken out of its cage and put on wire-bars or a rough surface for grasping. Gently approach the head from the back and firmly grasp the skin between the thumb and index finger. Grip the loose skin behind the neck to avoid turning of the head, while keeping the tail of the animal under little finger of the hand holding neck of the animal.
Note: Approach the animal with gentle, but firm hands. Too soft of a hand could set the animal free while too harsh of a hand could result in injury or stress.
In addition to one-handed mouse restraint, biomedical research uses two-handed restraint technique for mice.
Lift the mouse by the tail and place it on a cage or a rough surface, then gently pull the mouse from the back so that it can grasp the wire bars with fore-paws. And quickly grab the subject by the scruff of its neck with the other hand. Gather the loose skin at the back of the neck to limit the animal. Now you can observe or inject the subject as per experimental requirement.
Note: Two-handed manual restraint is preferred for an inexperienced or a new experimenter to instill confidence in handling and restraining laboratory animals (Suckow, Danneman, & Brayton., 2000).
Rats are relatively larger and less cooperative than mice. They can also be handled manually by scruffing, gripping shoulders, or by holding from under the shoulders (Sharp & Villano., 2012).
As rats are less receptive to scruffing than mice, so this procedure is limited to smaller rats. First, hold the rat form its tail and gently pull it back on a rough surface. Second, clutch the rear end firmly and approach the animal from the scruff. Apply gentle pressure on the back and grasp the scruff from the skull base between palm and fingers of the hand.
Note: Rat’s head should be controlled with caution as its bite can cause serious injury. The abovementioned holding may vocalize the animal.
Gripping over the shoulders
With your dominant hand, remove the rat from its cage and place it on a rough surface by grasping it from the tail. Approach the head from the back with the help of non-dominant hand. Hold the rat around the thorax with thumb, pinkie and ring finger by keeping its head between middle and index finger. In this position, the animal could be injected or observed.
Note: Thorax should not be compressed firmly.
Gripping under the shoulders
Place the rat on a rough surface and grasp its tail. Gently place the non-dominant hand on its back approaching from the caudal side. Hold the rat’s thorax under the shoulder blades and gently push its forearms with the thumb and index finger. Observe or inject the rat in this position.
Note: Fore-arms should cross rat’s chin to avoid biting and turning of the head. Do not compress the thorax.
Ferrets are usually aggressive and non-cooperative. They can be restrained by grasping from the neck and the shoulders. Hold the ferret with one hand under the shoulders by placing the thumb under the jaw and support the caudal part with another hand. You can now inject the animal or collect its blood for scientific investigations (Assessing the Health and Welfare of Laboratory Animals).
Guinea Pig Restraint
Guinea pigs are docile and easy to handle relatively. However, they get startled and disturbed easily. So they should be approached gently and softly to avoid frightening (Species-Specific Information: Techniques for Handling, Sexing, Injection, and Blood Collection). Do not move unnecessarily or make noise. Place the thumb under the jaw of the guinea pig. Support the caudal quarter with another hand. Another person should collect blood or inject the animal.
Like guinea pigs and ferrets, rabbits also need adequate handling and restraining procedures for experimental manipulations. As if not controlled, their hind legs can cause serious spine injury to them. Also, the weight of the rabbit is relatively higher than that of rats and mice (Rabbit – Sexing, Handling, and Restraint, 2017).
Check the condition of the rabbit before the experiment. Approach the animal with confidence as rabbits get stressed easily. Firmly grasp the rabbit from the nape of its neck. With the help of the second experimenter, firmly and gently place the hand on rabbit’s back. If a single person is handling, then a towel or a cat bag with zipping can be used to restrain the rabbit firmly.
Manual restraint is recommended for experienced and trained individuals, for brief periods usually for minutes. However, if experiments involve complicated and prolonged manipulations then, plastic or acrylic restrainers are suggested.