Handling, restraining, sexing and identification of rats and mice

Hi all. I am currently working in the Animal Facility for a particular instiitution which cannot be named due to issue of confidentiality. I am juggling both my major project and my SIP thus it requires alot of initiative and time management. I usually assist in lab practicals and the maintenance of the animal husbandry while carrying out my experiment at the same time.

I shall share with you the Handling and restraining of the rat/mouse,the sexing and identification of the rats/mice which is essential as these techniques form the basics before other procedures can be carried out.

Whenever animals are used for research or teaching, it is important to minimise pain and distress that they may suffer as this would indirectly in turn affect the reliability and reproducibility of the experimental data. AThe adoption of the 3R principles as required by NACLAR Guiding Principles, such as refinement of procedures, replacement of animals and reduction of the number of animals used should become an integral part of all scientific research

HANDLING AND RESTRAINING TECHNIQUES
The use of proper handling and restraint techniques would help to minimiza unneccessary stress to both animals and research personnel.Its is recommended that the animal be handled on a regular basis in a non-threatening manner such as weighing, giving food treats etc. Most animals will lrespond positively to learn to recognize individuals. Suden movements prior to handling the animals may startle them.

Handling and restraint of Mice

1. Removal from cage
WHen handling mice, your movement should be slow and gentle.
Grasp the middle or near base of the tail between your thumb and your index finger, and lift the mouse out of the cage. Never hold it by the end of its tail. The mouse may also be picked up using a thumb forcep with its tips covered with rubber or polyethelene tubing to prevent damage to the mouse tail. Do not apply too much pressure when lifting the mouse as this may cause the tail to break.

2. Technical manipulation
Mouse has to be placed on a rough surface in which it can firmly hang on to such as the cage lid. Smooth surfaces will frighten the mouse because it cannot get a foothold. Gradual pressure can be applied to the tail while the index finger and thumb are used to scruff the skin around the animal's shoulder.ATurn the animal over to rest in the palm of your hand. Its tail may be restrained by the other hand or simply between the last 2 fingers of the hand holding the mice. THis enable the other hand to be free to carry out manipulations or injections.

Handling and restraint of Rats

1.Removal from cage and Manipulation
THe rat may be lifted out of the cage by the base of the tail. Never suspend the ray by the tail for too long. SUpport the body weight as soon as possible so as to minimise stress to it. Gently and firmly grasp the rat around the thorax with thumb and fore finger under each of the front legs. The rat might be stretched out by pulling the hind legs with the other hand.

Identification of Rat and Mice

THere are various ways for identification of rats and mice
1. Cage card - to identify strain of rat/mouse, sex, number, principal investigator and research protocols. This should not be removed from the cage to prevent misidentification
2. Pen marks on tail- this serves as a form of temporary identification of an individual. THe marks usually last for 1-2 days long
3. Hair clippings or dyeing the fur - may last up to 14 days
4. Ear tagging - small metal clips stamped with individual numbers applied near base of ear
5. Ear Punching and notching - rats can be identified with number 1 through 99 by piercing a hole or a notch or a double notch or any combination. 1,2 and 3 are holes punched on the right ear while holes punched on the left ear represents 10,20,30 (i dunno how to post pix)
while 4,5,6 and 40,50,60 are represented by notch and 7,8,9 and 70,80,90 are represented by double notches.