Introduction

• A reference interval (RI) is a key component of the laboratory report informing the clinician as to the health status of their patient. Values within the RI are less likely to be associated with pathology.
• The RI may also be affected by factors such as patient age, species and the type of sample obtained (eg potassium, total protein and globulins, will differ between plasma and serum).
• The RI is instrumentation and reagent dependent. This explains the differences in RI for different diagnostic laboratories.
• Determining a reference population is not straightforward as some breeds of cats and dogs consistently have values outside of the standard RI absent a pathologic reason.
• An awareness of breed variations in both biochemistry and hematology parameters can facilitate interpretation of these results.

Determination of reference intervals

Summary of reported breed-related changes to the RI

When abnormal is not a worry

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• Spada E, Antognoni M T, Proverbio D, Ferro E, Mangili V, Miglio A (2015) Haematological and biochemical reference intervals in adult Maine Coon cat blood donors. J Feline Med Surg 17(12), 1020-1027 PubMed. 
• Paltrinieri S, Ibba F, Rossi G (2014) Haematological and biochemical reference intervals of four feline breeds. J Feline Med Surg 16(2), 125-136 PubMed. 
• Friedrichs K R, Harr K E, Freeman K P, Szladovits B, Walton R M, Barnhart K F et al (2012) ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics. Vet Clin Pathol 41(4), 441-443 Full Article.  
• Reynolds B S, Concordet D, Germain C A, Daste T, Boudet K G, Lefebvre H P (2010) Breed dependency of reference intervals for plasma biochemical values in cats. J Vet Intern Med 24(4), 809-818 PubMed. 
• Boudreaux M K (2001) Inherited platelet disorders. J Vet Emerg Crit Care San Antonio 22(1), 30-41 PubMed.