Vital Statistics in Rats

Physiologic Data

Temperature (R) 37.7°C (99.85°F)
Diploid number 42
Respiratory rate/minute 71 – 146
Tidal volume 0.6 – 2.0 mL
Oxygen use 0.68 – 1.10 mL/g/hr
Body surface area cm2 10.5 (weight in grams)2/3
GI transit time 12 – 24 hr
Heart rate/minute 250 – 493
Blood pressure 84 – 134/64 mm Hg
Daily urine output (average) 13 – 33 mL/24 hr (or approximately 5.5 mL/100 gm/24h)a
Food Intake 5 – 6 gm per ea. 100 gm per day
Water Intake 10 – 12mL per 100 gm per day
Weight (male average adult) 250 – 550 gm
Weight (female average adult) 225 – 400 gm
Nipples (found only on females) Average 6 pairs
Life span (average) 24 – 40 months

 

Environment Requirements

Room Temperature 65°-79°F / 18°-28°C
Relative Humidity 30% – 70 %
Housing Space 40 in.²   per 300 gm. wt. of rat

 

Reproduction

Puberty 6 – 8 weeks
Estrous cycle Polyestrous
Estrous period approx. 12 hours
Duration of cycle 4 – 5 days
Gestation 21 – 23 days
Size of litter approximately 8 – 14 pups
Birth weight 5 – 6 gm
Eyes open 10-12 days
When weaned approximately 4 weeks
Return of estrus cycle postpartum within 24 hours
Composition of Doe’s milk 13.0% fat, 9.7% protein, 3.2% lactose
Important male anatomic notation open inguinal canals

 

Hematologic Data / Values b,c

International Standard Units (SI)

Conventional Units

Total Blood volume
50 – 70 mL/kg
For Purpose of Blood Samples, single sample: 2 – 3 mL b
Note: exsanguination occurs at 8 – 12 mL b
Erythrocytes (RBC’s) 7 – 10 x 1012/L 7 – 10 x 106/mm3
Hematocrit (Hct)(PCV) 0.36 – 0.48 L/L 36 – 48 %
Hemaglobin (Hg) 110 – 180 g/L 11 – 18 g/dl
Leukocytes (WBC) 6 – 17 x 109/L 6 – 17 x 103/mm3
Segmented Neutrophils 9 – 34 %
Lymphocytes 65 – 85 %
Eosinophils 0 – 6 %
Monocytes 0 – 5 %
Basophils 0 – 1.5 %
Platelets 500 – 1300 x 109/L 500 – 1300 x 103/mm3

 

Biochemical Data (Electrolytes) / Values c,d,e

International Standard Units (SI)

Conventional Units

Serum protein (Total protein) 56 – 76 g/L 5.6 – 7.6 g/dL
Albumin 38 – 48 g/L 3.8 – 4.8 g/dL
Globulin 18 – 30 g/L 1.8 – 3.0 g/dL
Glucose 2.8 – 7.5 mmol/L 50 – 135 mg/dL
Calcium 1.32 – 3.24 mmol/L 5.3 – 13.0 mg/dL
Phosphate (Phosphorous) 1.71 – 2.68 mmol/L 5.3 – 8.3 mg/dL
Sodium 135 – 155 mmol/L 135 – 155 mEq/L
Potassium 4 – 8 mmol/L 4 – 8 mEq/L
Chloride 84 – 110 mEq/L d
Blood urea nitrogen (BUN) 5.4 – 7.5 mmol/L 15-21 mg/dl
Creatinine 18 – 71 µmol/L 0.2 – 0.8 mg/dL
Total bilirubin 3 – 9 µmol/L 0.20 – 0.55 mg/dL
Lipids 0.7 – 4.2 g/L 70 – 415 mg/dL
Phospholipids 0.4 – 1.3 g/L 36 – 130 mg/dL
Triglycerides 0.3 – 1.4 g/L 26 – 145 mg/dL
Cholesterol 0.88 – 3.36 mmol/L 34 – 130 mg/dL
ALT (Alanine aminotransferase) 16 – 89 IU/L
ALP (Alkaline phophatase) 16 – 125 IU/L
AST (Aspartate aminotransferase) 45.5 – 80.8 IU/L e
Amylase 128 – 313 IU/L e

 

Endocrine Values a

Total serum T4 3.4 – 6.2 µ/dL
Free T4 1.17 – 2.8 ng/dL
Free T3 110 – 1038 pg/dL

 

Coagulation Values

PT (prothombin time) 15.7 – 25.4 seconds
PTT (Activated partial thromboplastin time) 15 – 19.3 seconds
Bleeding Time / Clotting Time 2 – 5 minutes f

 

Urinalysis e

Normal color dark yellow, yellow, light yellow, milky
Urine volume 13 – 33 mL/24 hr (or approximately 5.5 mL/100 gm/24h a)
pH (acidity/alkalinity of solution) 7.3 – 8.5
SG (Specific Gravity) 1.02 – 1.07
Protein <30 mg/24h
Glucose negative
Bilirubin negative
Erythrocytes (RBC, blood) negative
Ketones negative
Leukocytes (WBC) few
Bacteria negative

 


Values expressed here are adaptations from references listed on References page of the Rat Health Guide Index. Normal variations may occur within the rat population based on strain type, age, sex or if the animal has fasted. Values from blood or tissue samples may vary slightly, based on the Lab the specimens are sent to and its equipment calibrations.

aAdapted from Carpenter, J. W. (2012). Exotic animal formulary (4th ed.). Philadelphia, Pa.: Saunders.

bEquals approximate values.

cAdapted from Harkness, JE., Turner, PV., VandeWoude, S., et al. (2010). Harkness and Wagner’s Biology and Medicine of Rabbits and Rodents. 5th ed. Ames: Wiley-Blackwell.

dAdapted from Sharp, P., & Regina, M. (1998). The Laboratory Rat. Boca Raton: CRC Press, and Sharp, P., & Villano, J. (2012). The Laboratory Rat, Second Edition. Boca Raton: CRC Press.

eAdapted from Keeble, E. J., & Meredith, A. (2009). BSAVA manual of rodents and ferrets. Quedgeley: British Small Animal Veterinary Association.

fPass, D. and G. Freeth. (1993). The rat. ANZCCART News 6(4): 1-4

Cross-references

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