Rat Anesthesia + Necropsy

Question 1

What are the materials needed for rat anesthesia

Answer 1

• Anesthetic drugs (see list provided the day of the procedure)
• Ophthalmic sterile lubricant
• Syringe & needle for IP injection
• Anesthetic machine

Question 2

What do you do to the rat before the IP injection of the anesthetic

Answer 2

Verify all calculations
Record it in drug log book
Take a rat from the cages.
Perform a presurgical clinical examination of the animal.
Take the body weight of the animal (using rodents scale).

Question 3

What do you do with the rat after IP anesthetic administration

Answer 3

Coat the eyes of the animal with ophthalmic sterile lubricant.
Test for depth of anesthesia by pedal withdrawal reflex.

Question 4

During anesthesia the following parameters will be monitored and recorded on the anesthetist’s data sheet:

Answer 4

Respiratory rate: (The respiratory rate in normal rats (undisturbed) is usually between 70 and 90 breaths per minute, and in general a fall up to 50% from this value can be considered acceptable)

• Respiratory pattern (In light anesthesia, breathing is usually irregular in rate and depth.)
• Colour of the ears, muzzle and footpads
• Heart rate
• Pedal withdrawal reflex

Question 5

What do you need for blood collection by IC puncture

Answer 5

****Anesthetized patient
Calculate the maximum volume that can be collected (record the required information on the Lab Report)
Prepare a 10cc syringe with a 22G 1” needle and one serum tube.

Question 6

Describe the technique for blood collection via IC puncture

Answer 6

• Place the animal in dorsal recumbency.
• Palpate the xiphoid process.
• Insert the tip of needle between the left side of the xiphoid process and the last rib.
• Once you have punctured the skin, gently pull back on the plunger to create a negative
  pressure and keep it.
• Penetrate the thoracic cavity slowly while directing your needle toward the heart at an angle
  of approximately 40°. When blood is visible in the needle hub, stabilize your syringe and
  continue to pull back on the plunger slowly.
• Record on the Lab Report the amount of blood that you have collected and place the blood in
  the serum tube.

Question 7

What are the steps for the rat castration

Answer 7

1. Shave scrotal area
2. Prep scrotum with 1 and 2 solution
3. Drape + Fix drape with towel forceps
4. Make 1cm incision on tip of scrotum
5. Make incision through tunica vaginalis
6. Withdraw testical through the incision.
7. Clamp spermatic blood vessels and vas deferens with forceps
8. Place 3-0 suture material and place a singla ligature around both vessels and vas deferens.
9. Cut spermatic blood vessels + vas deferens
10. Close tunica vaginalis with simple interrupted 3-0.
11. Close skin incision with simple interrupted 3-0.

Question 8

How do you perform the splenectomy on a rat

Answer 8

1. Shave abdomen from rib cage to pubic symphysis. Vacuum excess hair. Prep Surgical site.
2. Tie animal to table, careful not to occlude circulation
3. Drape surgical site
4. Make mid-line incision from xyphioid to umbilicus.
5. Dissect the skin laterally away from the muscle
6. Lift linea alba with rat-tooth forceps. Make an opening with scalpel. Cut linea alba using metzenbaum.
7. Place gauze around the spleen to prevent it from slipping.
8. Use 3-0 absorbable suture and place splenic blood vessels about 1cm from entry to the spleen.
9. Wet the exposed tissues with warm saline.
10. Remove spleen after cutting vessels.
11. Close abdominal muscle with 3-0 simple interrupted.
12. Close skin with 3-0 simple interrupted.