APPENDIX A Normal Blood Values
Shannon Jones Hostetter, DVM, PhD, Diplomate ACVP
Reference Intervals for Common Domestic Species: Blood Gas and Hematology
Laboratory tests are frequently used in veterinary medicine and research to help evaluate animal health.
When laboratory tests are performed, the individual animal’s test result is usually compared to a “reference interval.” Reference intervals are used to determine if an individual’s laboratory result is abnormal, most often via comparison to a reference population of similar individuals. An abnormal test result, or constellation of results, may help the clinician or researcher make decisions on disease diagnosis, treatment, study outcome, etc.Reference intervals are most useful when they accurately reflect the characteristics of the individual being evaluated. Arguably the most important variable to consider is species. For example, if a white blood cell count is determined in a dog, the result should be compared to a reference interval for a white blood cell count generated using dogs, not cats or cattle. Ideally, the reference interval should also account for major factors that would be likely to influence the physiology of animals within the same species, including age, genetic factors, gender, diet, and husbandry. Additional factors that determine the appropriateness of a set of reference intervals include analytical factors, such as instrumentation and test methodology.
The generation of population-based reference intervals for a specific test is both labor intensive and costly. Guidelines for creating reference intervals recommend sampling at least 120 healthy animals from the target population, measuring the analyte (substance to be measured) in the samples, and determining the central 95% of the distribution of the results using specific statistical procedures.
The reference intervals provided here were established in a Midwestern veterinary teaching hospital’s clinical pathology laboratory using predominantly animals from within the overall geographic vicinity.
They are provided as a general indicator of the potential inherent variability that can be observed between domestic species. Utilization of these reference intervals for clinical decision making in the practice of veterinary medicine should be used with caution without validation of the method within the specific laboratory measuring the patient analyte.
■ References and Resources
Friedrichs KR, et al. ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics. Veterinary Clinical Pathology. 2012; 41(4): 441-453-
Geffre A. et al. Reference intervals: a review. Veterinary Clinical Pathology. 2009; 38(3): 288-298.
Hematology Reference Intervals
| TABLE A-1 Arterial blood gas analysis | |||||
| UNIT | CANINE | FELINE | BOVINE | EQUINE | |
| pH | 7.31-7.42 | 7.24-7.40 | 7.35-7.50 | 7.32-7.44 | |
| pCO2 | mmHg | 29-42 | 29-42 | 35-44 | 38-46 |
| pO2 | mmHg | 85-95 | 85-95 | 85-95 | 85-95 |
| HCO3 | mEq/L | 17-24 | 17-24 | 20-30 | 24-30 |
| Serum Osmolality | mOsm/kg | 280-305 | 280-305 | 270-300 | 270-300 |
| Data from Clinical Pathol Veterinary Medicine, Iow | ogy Laboratory, Department of Veterinary Pathology, College of a State University. | ||||
| TABLE A-2 Hematology reference intervals for the dog | ||
| WBC | 6.0-17.0 | 103∕μL. |
| Band neutrophils | 0.0-0.3 | 103∕μL. |
| Segmented neutrophils | 3.0-11.4 | 103∕μL. |
| Lymphocytes | 1.0-4.8 | 103∕μL. |
| Monocytes | 0.15-1.35 | 103∕μL. |
| Eosinophils | bgcolor=white>0.1-0.75103∕μL. | |
| Basophils | 0.0-0.1 | 103∕μL. |
| RBC | 5.5-8.5 | 1 ? 106 μL |
| Hb | 12-18 | g∕dL.. |
| Hct | 37-55 | %.. |
| MCV | 60-77 | fL.. |
| MCH | 19.5-30 | pg∙ ■ |
| MCHC | 32-36 | g∕dL.. |
| Platelets | 200-500 | 1? 103∕μL |
| Plasma protein | 5.3-7.2 | g∕dL. |
| Fibrinogen | 100-400 | mg∕dL. |
| RBC lifespan | ~108 daysa | |
| Data from Clinical Pathology Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University. aWeissman SM, Waldmann TA, Berlin NI. Quantitative measurement of erythropoiesis in the dog. American Journal of Physiology. January 1960; 198: 183-186. | ||
| TABLE A-3 Hematology reference intervals for the cat | ||
| WBC | 5.5-19.5 | 103∕μL. |
| Band neutrophils | 0.0-0.3 | 103∕μL. |
| Segmented neutrophils | 2.5-12.5 | 103∕μL. |
| Lymphocytes | ι.5-7.0 | 103∕μL. |
| Monocytes | 0.0-0.85 | 103∕μL. |
| Eosinophils | 0.0-0.75 | 103∕μL. |
| Basophils | 0.0-0.1 | 103∕μL. |
| RBC | 5-10 | 1 ? 106 μL |
| Hb | 10-15 | g∕dL.. |
| Hct | 30-45 | %... |
| MCV | 39-55 | fL... |
| MCH | 12.5-17.5 | pg∙ ■ |
| MCHC | 30-36 | g∕dL. |
| Platelets | 300-800 | 1 ? 103∕μL |
| Plasma protein | 6.3-8.2 | g∕dL. |
| Fibrinogen | 100-400 | mg∕dL,. |
| RBC lifespan | ~77 daysα | |
| Data from Clinical Pathology Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University. aValentine WN, Pearce ML, Riley RF, Richter E, Lawrence JS. Heme synthesis and erythrocyte life span in the cat. Proc Soc Exp Biol Med, June 1951; 77(2): 244-245. | ||
| TABLE A-4 Hematology reference intervals for cattle | ||
| WBC | 4.0-12.0 | 103∕μL. |
| Band neutrophils | 0.00-0.12 | 103∕μL. |
| Segmented neutrophils | 0.6-4.0 | 103∕μL. |
| Lymphocytes | 2.5-7.5 | 103∕μL. |
| Monocytes | 0.03-0.85 | 103∕μL. |
| Eosinophils | 0.0-2.4 | 103∕μL. |
| Basophils | 0.0-0.2 | 103∕μL. |
| RBC | 5-10 | 1 ? 106 μL |
| Hb | 8-15 | g∕dL.. |
| Hct | 24-46 | %... |
| MCV | 40-60 | fL,.. |
| MCH | 11-17 | pg. ■ ■ |
| MCHC | 30-36 | g∕dL.. |
| Platelets | 300-800 | 1? 103∕μL |
| Plasma protein | 6.9-7.7 | g∕dL.. |
| Fibrinogen | 100-500 | mg∕dL. |
| Data from Clinical Pathology Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University. | ||
| TABLE A-5 Hematology reference intervals for the horse | ||
| WBC | 5.0-11.0 | 103∕μL. |
| Band neutrophils | 0.0-0.2 | 103∕μL. |
| Segmented neutrophils | 2.1-6.7 | 103∕μL. |
| 684 | ||
| Lymphocytes | 1.3-4.5 | 103∕μL. |
| Monocytes | 0.0-0.5 | 103∕μL. |
| Eosinophils | 0.0-0.5 | 103∕μL. |
| Basophils | 0.0-0.2 | 103∕μL. |
| RBC | 7-11 | 1 ?106 μL |
| Hb | 11.5-16.0 | g∕dL.. |
| Hct | 34-45 | %... |
| MCV | 36-49 | fL.. |
| MCH | 12.7-17.5 | pg. ■ |
| MCHC | bgcolor=white>34-36g∕dL. | |
| Platelets | 130-300 | 1? 103∕μL |
| Plasma protein | 6.0-8.2 | g∕dL.. |
| Fibrinogen | 100-400 | mg∕dL. |
| RBC lifespan | 140-160 daysα |
Data from Clinical Pathology Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University.
aCornelius CE, Kaneko JJ, Benson DC, Wheat JD. Erythrocyte survival studies in the horse using glycine-C14. Am J Vet Res. 1962; 21: 1123-1124.
| TABLE A-6 Hematology reference intervals for the pig | |||
| UNIT | 0-6 weeks old | 6 weeks-2 years | |
| WBC | 103∕μL, | 9.62-25.2 | 11.35-28.9 |
| Segmented neutrophils | 103∕μL, | 2.35-11.9 | 2.00-10.4 |
| Lymphocytes | 103∕μL, | 4.02-12.50 | 5.30-17.9 |
| Monocytes | 103∕μL, | 0.05-2.30 | 0.0-3.7 |
| Eosinophils | 103∕μL, | 0.0-0.5 | 0.0-1.3 |
| RBC | 1 ? 106 μL | 4.87-7.88 | 5.88-8.19 |
| Hb | g∕dL | 8.08-11.9 | 11.2-14.7 |
| Hct | % | 28.22-39.8 | 32.3-42.6 |
| MCV | fL | 43.4-64.5 | 47.5-59.2 |
| MCH | pg | 12.4-19.3 | 16.3-20.6 |
| MCHC | g∕dL | 27.39-31.4 | 33.3-35.8 |
| Platelets | 1 ? 103∕μL | 374.3-1080.8 | 118.9-522.9 |
| Fibrinogen | mg∕dL | 100-500 | 100-500 |
| RBC lifespan | 86 +∕- 11.5 daysα | ||
| Data from Clinical Pathology Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University. aBush JA, Berlin NI, Jensen WN, Brill AB, Cartwright GE, and Wintrobe MM. Erythrocyte life span in growing swine as determined by glycine-2-C14. J Exp Med. 1955, May 1; 101(5): 451-459. | |||