COMMON TECHNIQUES IN EXPERIMENTAL ANIMALS & ANIMAL HANDLING.pptx

ALL LAB ANIMAL HANDLING TECHNIQUES.
COMMON PROCEDURE IN LAB WITH ANIMALS

1. COMMON TECHNIQUES IN EXPERIMENTAL ANIMALS & ANIMAL HANDLING Dr. Parmanand Atal First Year Resident Department of Pharmacology SMS Medical College, Jaipur

2. COMMON TECHNIQUES IN EXPERIMENTAL ANIMALS

3. Bleeding and Intravenous Injection

4. Rat and Mouse Both collection of blood as well as injection can be carried out by tail venipuncture. In restrained animals lateral or dorsal veins are dilated by dipping the tail into water at 40 to 50 C.

5. L ateral or dorsal veins can also be dilated by rubbing with xylol and then cleaning the part with some disinfectant. The tail is grasped between the thumb and the index finger, and the needle (25 to 27-gauge) is introduced near the distal portion of the tail with the bevel up, and the injection made with a uniform speed.

6. Another way of collecting blood repeatedly is by cutting the tip of the tail with some sharp instrument. Blood can also be collected by heart puncture in anaesthetized animals, or sometimes by decapitation. The most efficient method of collecting blood is from the orbital sinus with the help of a capillary tube.

7. Bleeding from orbital sinus The loose skin of the head is tightened while holding the head with the left hand. With the help of the index finger the eye is made to protrude by traction on the skin. The thumb is pressed just behind the angle of the jaw resulting in the engorgement of the retro-orbital plexus.

8. The tip of a Pasteur Pipette is then inserted at the medial canthus into the retro-orbital plexus with gentle rotation by the other hand. As the vessels are ruptured blood wells up in the periorbital space. The tip of the pipette is then slightly withdrawn so that the blood flows into the pipette by capillary action.

9. Bleeding stops once the normal ocular pressure is allowed to impinge on the venous plexus by releasing the animal.

10. Pasteur Pipette

11. Guinea Pig Small samples of blood may be obtained by simple venesection of the marginal ear vein. Larger quantities of blood may be obtained either by heart puncture under anaesthesia or by severing the carotid artery after stunning or inducing anaesthesia. I ntravenous injection, i n males can be made through the penile veins.

12. Rabbit The lateral margin of the ear is shaved and swabbed with a disinfectant. The ear is grasped between the thumb and the index finger in n well-restrained animal. Using a 20-gauge needle with the bevel up, venipuncture is made at a site immediately proximal to the thumb along the marginal vein.

13. Very gentle aspiration must be applied in order to avoid collapse of the vein. IV Injection Can also be made through the same vein. Another method is to make a cut in the marginal vein or the central artery of the ear near its tip.

14. The vein is occluded near the base, the artery is gently tapped near the animal's head and blood collected in container. A large quantity of blood may be obtained easily by this method . The bleeding is stopped by pressing a little cotton wool held in position with Bulldog Clamp .

15. BULLDOG CLAMP

16. INTRAGASTRIC ADMINISTRATION

17. Mouse Polythene tubing 2 to 3 cm long sleeved on an 18 to 20-gauge blunted hypodermic needle or a Eustachian catheter may be used for the purpose.

18. The animal is grasped securely by the nape of the neck holding the whole animal with the left hand. The polythene tubing is introduced laterally through the intradental space, and with rotating motions gently advanced into the oesophagus. When it is relatively certain that the tube is at the desired level, the fluid ts introduced slowly.

19. RAT AND GUINEA PIG A 15 to 16-gauge hypodermic needle of 7.5 to 10 cm length is blunted. A small ball of solder is applied around the tip A gentle bend (20 to 30°) is made about 2 cm proximal to the solder. The technique is almost similar as in the case of mouse.

20. Rabbit An assistant sitting on a chair with the rabbit on his knees holds the animal. With pressure to the cheeks at the corners of the mouth

21. When the animal opens its mouth, then a wooden gag with a small hole 'in the centre is placed in the mouth behind the incisors. A No. 12 French catheter (4 mm dia) or a No. 9 soft rubber catheter (5 mm dia) moistened with glycerine is inserted through the central hole with right hand as the left hand controls the gag.

22. The tube passes over the base of the tongue swallowed slowly. The outer end of the tube can be placed under water or near the operator's ear to check for accidental tracheal intubation.

23. PROCEDURES FOR RENDERING ANIMALS UNCONSCIOUS

24. A n animal is rendered unconscious so that it does not feel pain and also sacrificed painlessly at the end of the experiment.

25. Mice, Rats, Guinea Pigs and Rabbits The commonest, quickest and the most humane method of killing these animals is by preliminary stunning (crushing the skull) followed by cutting the throat for bleeding. Stunning is carried Out either by a smart blow behind the head or on the back of the neck with a blunt instrument.

26. The immediate effect of stunning is a stiffening of all the muscles followed by a series of convulsions followed by gradual relaxation of the limbs and body. These are not indication of suffering on the part of the animal. If there is any doubt about the animal regaining consciousness, the head should be cut off immediately.

27. ANIMAL HANDLING

28. Includes transferring the cage, feeding, treatment (gavages or parenteral) or any other procedure with the animals. In India CPCSEA ( Committee for the Purpose of Control and Supervision of Experiments on Animals ) has given complete guideline for animal caring, housing and handling requirements.

29. Precaution to be taken before handling the animals

30. First pet or soothe the animal by slow deliberate movements on their body. Overcrowding near the animal cage should be avoided . Noise should be kept to a minimum as much as possible. Don’t hold animal too hard, it may face difficulty in breathing and may die too. Never agitate the animal, it may become violent for self protection.

31. MOUSE T he smallest animal in the laboratory and used very commonly. 1st Method: One can handle it with the help of blunt forceps by grasping the skin behind the neck/body. This technique is often used to transfer mice from one cage to another.

32. 2nd Method: Grasp the base of the tail with one hand and with the other grasp the loose skin behind its neck.

33. 3rd Method: Hold the complete body by grabbing back of the neck by using all fingers

34. RAT Rats weigh more, are longer and have thicker tails than Mouse. 1st Method: Lift rat out of the cage by grasping the base of the tail and place on a soft surface. (Hard smooth surfaces can make the rat tense)

35. 2nd Method: Place your index and middle fingers alongside the rat’s head and your thumb and ring fingers under its forelegs. Use your index and middle fingers to secure its head and the remaining fingers to support the body.

36. 3rd Method: Hold the complete body by grabbing the back by using complete palm.

37. Guinea Pig T hese are very humble rodents and can be easily handled because of their docile nature. 1st Method: By using both hands, calmly grasp it with one hand under the chest and Use your other hand to support its hindquarters.

38. 2nd Method: Handle guinea pig with one hand, by holding its hind quarter.

39. Hamster 1st Method: Hold the complete body by grabbing at the nap of the neck by thumb and index finger and grasp the complete body by using rest of fingers.

40. 2nd Method: Hold the complete body by grabbing back by using complete palm.

41. Rabbit 1st Method: By using single hand, hold the pelvic region. This technique is mainly used to transfer rabbits from one cage to another.

42. 2nd Method: By using both the hands, hold the complete hindquarter

43. 3rd Method: By using the both hands, calmly grasp it with one hand supporting back of neck and the other hand supporting its hindquarters.