RATS

RATS Usually very friendly and accept handling and gentle manipulation Rarely bite

GENERAL RESTRAINT Grab over neck and shoulders Place forefinger just below mandible on one side of head and thumb on opposite side either above or below forelimb Provide additional support by holding tail and hind limbs with opposite hand

Scruffing Technique Same as in gerbils and mice Don not like it

Full Restraint Wrap in thin towel or stockinette Syringe case with air hole Cone shaped polyethylene bag with tip cut off

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Laboratory Animal Handling Technique - Rat Intraperitoneal injection Blood collection from tail vein Blood collection from cardiac puncture Oral feeding Chemical Restraint

Intraperitoneal Injection in Rat The most common method of administering drugs to rats

Tools for intraperitoneal injection in rat 75% alcohol cotton ball for surface disinfection medium size towel for restraining the rat 25G 5/8” needle with 1cc syringe for injection

Let the rat relaxes on the top of the lid.

Stretch the body of the rat by pulling up it’s tail and then cover the rat with a towel by your left hand

Fold the skirts of towel under the rat from all directions

Grasp up the left hindlimb of the rat to expose the abdomen

The injection site should be in the lower left quadrant of the abdomen because vital organs are absent from this area

Only the tip of the needle should penetrate the abdominal wall to prevent injection into the intestines.

Collection of blood from tail vein in rat small amount: 0.1-1 ml

Tools for collection of blood from tail vein 75% alcohol cotton ball for surface disinfection 27G1/2” needle with 1 ml syringe for blood withdrawal a vial for blood collection

Optimal site of blood withdrawal is around the distal one-third of the tail since this part of tail gives better visualization of the veins

The rat's tail has a thermoregulatory function: it serves as a heat-loss organ. The tail is well suited for this purpose, because it has no fur, has a large surface to volume ratio, and is perfused with many blood vessels, especially at the tail tip and midlength (Yulong et al. 1995).

Temperature influence Rats control their body temperature through their tails by dilating or constricting their tail blood vessels.

Disinfect the tail with 75% alcoholic cotton ball

When the needle penetrates the epithelium of the tail, pull back the plugger a bit to create negative pressure inside the syringe, then push the needle in the vein slowly until blood get into the dead space of the needle head

Pull back the plugger by the ring finger to withdraw blood from the tail vein

Using a scalpel to make a small wound on the tail is also an option for collecting blood from tail vein

Blood can be collected b using a pipetteman after then

Collection of Blood from Cardiac puncture in Rat General anesthesia needed Large amount: up to 3% of body weight

Tools for collection of blood from cardiac puncture 75% alcohol cotton ball for surface disinfection 24G needle with 10cc syringe for blood withdraw 15 cc centrifuge tube for blood collection

Disinfect the left thorax with 75% alcoholic cotton ball

Search for the point of maximum heart beat

Insert the needle straight on the selected point and withdraw blood by your left hand

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Oral Feeding in Rat Feeding amount limited to 1% of body weight

Tools for oral feeding in rat 16 G ball-tipped feeding needle with syring Leather glove

Restrain the shoulders of the rat by your thumb and index finger, then support the lower limbs with your right hand

Restrain the tail of the rat in between your ring finger and little finger

Let the rat lying on your left palm and introduce the ball-tipped feeding needle from the pharynx in to the esophagus when the rat is in the act of swallowing

SEDATION AND TRANQUILIZATION CHEMICAL RESTRAINT SEDATION AND TRANQUILIZATION

ACEPROMAZINE Mild tranquilizer Dose: 0.5 – 2.5 mg/kg IM or SQ Lower dose for IM Higher dose for SQ

DIAZEPAM Mild sedation Dose: 3-5 mg/kg IM IM injection may be irritating to muscle

FENTANYL/DROPERIDOL Excellent sedative Can see narcotic induced respiratory depression with higher doses Primarily used in rats and mice Doses Rats 0.13 – 0.33 mg/kg IM Provides sedation and anesthesia for minor procedures

ANTICHOLINERGICS Used as a premed Atropine Glycopyrrolate Decrease salivation (Ketamine, inhalants) Maintain heartrate Atropine 0.05 mg/kg SQ Glycopyrrolate 0.01 – 0.02 mg/kg SQ

INJECTABLE ANESTHESIA Clinical Laboratory Animal Medicine book Page-91 CHEMICAL RESTRAINT INJECTABLE ANESTHESIA Clinical Laboratory Animal Medicine book Page-91

XYLAZINE/KETAMINE Short duration of action (30 minutes) Rats Mice Xylazine: 5-10 mg/kg + Ketamine: 40-80 mg/kg IM or IP Mice Xylazine: 5-10 mg/kg + Ketamine: 50-200 mg/kg IM or IP

KETAMINE/ACEPROMAZINE Adequate restraint for minor surgical procedures General Rule: the smaller the species, the greater the dose needed for adequate effect Rats and Mice Acepromazine: 2.5-5 mg/kg + Ketamine 75-80 mg/kg IM or IP

TILETAMINE-ZOLAZEPAM For minor surgical procedures Dose 20-40 mg/kg IM or IP Can have prolonged recovery Used in combination with xylazine Decrease dose to 5-10 mg/kg Better effect and faster recovery

INHALANT ANESTHESIA Use for any major surgical procedure Induce with gas alone or with injectable anesthetics Isoflurane is the agent of choice

REFERENCES Birchard, S.J., & Sherding, R.G. (2000). Saunders Manual of Small Animal Practice, Second Edition. Phildephia, PA. WB Saunders Company. Fowler, M.E. (1995). Restraint and Handling of Wild and Domestic Animals, Second Edition. Ames, IA. Iowa State University Press. Frye, F.L. (1994) Reptile Clinician's Handbook: a compact clinical and surgical reference. Krieger Pub Co. Beynon, P.H. (1992) Manual of reptiles. Cheltenham, Gloucestershire. British Small Animal Veterinary Association. Hillyer, E.V., & Quesenberry, K.E. (1997). Ferrets, Rabbits and Rodents: Clinical Medicine and Surgery. Philedephia, PA. WB Saunders Company