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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
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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
http://awic.nal.usda.gov/nal_display/index.php?info_center=3&tax_level=3&tax_subject=183&topic_id=1093&level3_id=6273&level4_id=0&level5_id=0&placement_default=0http://awic.nal.usda.gov/nal_display/index.php?info_center=3&tax_level=3&tax_subject=183&topic_id=1093&level3_id=6273&level4_id=0&level5_id=0&placement_default=0 • http://www.bva-awf.org.uk/resources/tutorials/BVA02-Introduction.html
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
Stretch the body of the rat by pulling up it’s tail and then cover the rat with a towel by your left hand
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.
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
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
Insert the needle straight on the selected point and withdraw blood by your left hand
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
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 ml/kg IM • Provides sedation and anesthesia for minor procedures
ANTICHOLINERGICS • Used as a premed • Decrease salivation (Ketamine, inhalants) • Maintain heartrate • Atropine • 0.05 mg/kg SQ • Glycopyrrolate • 0.01 – 0.02 mg/kg SQ
CHEMICAL RESTRAINT INJECTABLE ANESTHESIA Clinical Laboratory Animal Medicine book Page-91
XYLAZINE/KETAMINE • Short duration of action (30 minutes) • Rats • 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