The following list comprises all known peer-reviewed veterinary clinical pathology biological variation in chronological order.  The data from these papers are shown in the database tables on this website.  Please let us know of any omissions via

  1. Leissing N, Izzo R, Sargent H. Variance estimates and individuality ratios of 25 serum constituents in beagles. Clin Chem. 1985;31(1):83-86.

  2. Carakostas MC, Banerjee AK. Interpreting rodent clinical laboratory data in safety assessment studies: biological and analytical components of variation. Toxicol Sci. 1990;15(4):744-753.

  3. Jensen AL, Houe H, Nielsen C. Critical difference of some bovine haematological parameters. Acta Vet Scand. 1991;33(3):211-217.

  4. Jensen AL, Aaes H. Reference interval and critical difference for canine serum fructosamine concentration. Vet Res Commun. 1992;16(5):317-325.

  5. Jensen AL, Houe C, Nielsen C. Critical differences of clinical-chemical parameters in blood from Red Danish dairy cows. Res Vet Sci. 1992;52(1):86-89.

  6. Jensen AL, Houe H, Nielsen C. Critical differences of clinical chemical components in blood from Red Danish dairy cows based on weekly measurements. J Comp Pathol. 1992;107(4):373-378.

  7. Jensen AL, Aaes H. Critical differences of clinical chemical parameters in blood from dogs. Res Vet Sci. 1993;54(1):10-14.

  8. Jensen AL, Høier R, Pedersen HD. Evaluation of an enzyme linked immunosorbent assay for the determination of free thyroxine in canine plasma samples assisted by data on biological variation. J Vet Med A. 1993;40(1‐10):539-545.

  9. Jensen AL, Pedersen HD, Koch J, Aaes H, Flagstad A. Applicability of the critical difference. J Vet Med A. 1993;40(1 10):624-630.

  10. Jensen AL, Høier R. Evaluation of Thyroid Function in Dogs by Hormone Analysis: Effects of Data on Biological Variation. Vet Clin Pathol. 1996;25(4):130-134.

  11. Jensen AL, Iversen L, Petersen T. Study on biological variability of haematological components in dogs. Comp Hematol Int. 1998;8(4):202-204.

  12. Loste A, Marca MC. Diabetes mellitus in dogs: a study of the critical difference for canine serum fructosamine. Vet Rec. 1998;142(20):547-548.

  13. Iversen L, Jensen AL, Høier R, Aaes H. Biological variation of canine serum thyrotropin (TSH) concentration. Vet Clin Pathol. 1999;28(1):16-19.

  14. Jensen AL, Aaes H, Iversen L, Petersen TK. The long-term biological variability of fasting plasma glucose and serum fructosamine in healthy beagle dogs. Vet Res Commun. 1999;23(2):73-80.

  15. Marca MC, Loste A. Glycosylated haemoglobin in dogs: study of critical difference value. Res Vet Sci. 2001;71(2):115-117.

  16. Petersen HH, Nielsen JP, Jensen AL, Heegaard PMH. Evaluation of an Enzyme‐Linked Immunosorbent Assay for Determination of Porcine Haptoglobin. J Vet Med A. 2001;48(9):513-523.

  17. Scope A, Schwendenwein I, Gabler C. Short-term variations of biochemical parameters in racing pigeons (Columba livia). J Avian Med Surg. 2002;16(1):10-15.

  18. Kjelgaard-Hansen M, Mikkelsen LF, Kristensen AT, Jensen AL. Study on biological variability of five acute-phase reactants in dogs. Comp Clin Pathol. 2003;12(2):69-74.

  19. Martı́nez-Subiela S, Tecles F, Cerón JJ. Critical differences of acute phase proteins in canine serum samples. Vet J. 2003;166(3):233-237.

  20. Choi E-w, Shin D-hB, Kim CyH, Youn H-y, Lee C-w. Clinical Chemical Parameters in Dogs. J Vet Clin. 2005;22(3):198-201.

  21. Scope A, Schwendenwein I, Frommlet F. Biological variation, individuality and critical differences of eight biochemical blood constituents in budgerigars (Melopsittacus undulatus). Vet Rec. 2006;159(25):839-843.

  22. Bertelsen MF, Kjelgaard-Hansen M, Howell JR, Crawshaw GJ. Short-term biological variation of clinical chemical values in dumeril's monitors (Varanus dumerili). J Zoo Wildl Med. 2007;38(2):217-221.

  23. Pagitz M, Frommlet F, Schwendenwein I. Evaluation of biological variance of cystatin C in comparison with other endogenous markers of glomerular filtration rate in healthy dogs. J Vet Intern Med. 2007;21(5):936-942.

  24. Wiinberg B, Jensen AL, Kjelgaard-Hansen M, Rojkjaer R, Johansson PI, Gade LP, Gram DX, Kristensen AT. Study on biological variation of haemostatic parameters in clinically healthy dogs. Vet J. 2007;174(1):62-68.

  25. Carney PC, Ruaux CG, Suchodolski JS, Steiner JM. Biological Variability of C‐Reactive Protein and Specific Canine Pancreatic Lipase Immunoreactivity in Apparently Healthy Dogs. J Vet Intern Med. 2011;25(4):825-830.

  26. Pinches MD, Betts CJ, Bickerton SJ, Beattie L, Burdett LD, Thomas HT, Derbyshire NA, Moores M, Price SA. Evaluation of Novel Urinary Renal Biomarkers: Biological Variation and Reference Change Values. Toxicol Pathol. 2012;40(3):541-549.

  27. Ruaux CG, Carney PC, Suchodolski JS, Steiner JM. Estimates of biological variation in routinely measured biochemical analytes in clinically healthy dogs. Vet Clin Pathol. 2012;41(4):541-547.

  28. Heilmann RM, Ruaux CG, Burgener IA, Hern JD, Suchodolski JS, Steiner JM. Serum alpha1-proteinase inhibitor concentrations in healthy dogs – method validation and determination of reference interval and intra-individual variation. Vet Clin Pathol. 2013;42(2):190-195.

  29. Hyldahl Laursen S, Andersen PH, Kjelgaard‐Hansen M, Wiinberg B. Comparison of components of biological variation between 3 equine thromboelastography assays. Vet Clin Pathol. 2013;42(4):443-450.

  30. Baral RM, Dhand NK, Freeman KP, Krockenberger MB, Govendir M. Biological variation and reference change values of feline plasma biochemistry analytes. J Feline Med Surg. 2014;16(4):317-325.

  31. Jones MP, Arheart KL, Cray C. Reference Intervals, Longitudinal Analyses, and Index of Individuality of Commonly Measured Laboratory Variables in Captive Bald Eagles (Haliaeetus leucocephalus). J Avian Med Surg. 2014;28(2):118-126.

  32. Belge Kurutuş E, Sermin G. Biological Variation of Oxidative Stress Biomarkers and Lactic Dehydrogenase in Mice. Blood. 2015;3(21):18.

  33. Bourgès-Abella NH, Gury TD, Geffré A, Concordet D, Thibault-Duprey KC, Dauchy A, Trumel C. Reference Intervals, Intraindividual and Interindividual Variability, and Reference Change Values for Hematologic Variables in Laboratory Beagles. J Am Assoc Lab Anim Sci. 2015;54(1):17-24.

  34. Ruaux CG, Scollan K, Suchodolski JS, Steiner JM, Sisson DD. Biologic variability in NT-proBNP and cardiac troponin-I in healthy dogs and dogs with mitral valve degeneration. Vet Clin Pathol. 2015;44(4):420-430.

  35. Blois SL, Lang ST, Wood RD, Monteith G. Biologic variability and correlation of platelet function testing in healthy dogs. Vet Clin Pathol. 2015;44(4):503-510.

  36. Strage EM, Theodorsson E, Ström Holst B, Lilliehöök I, Lewitt MS. Insulin-like growth factor I in cats: validation of an enzyme-linked immunosorbent assay and determination of biologic variation. Vet Clin Pathol. 2015;44(4):542-551.

  37. Strage EM. Biological variation of serum insulin concentrations in healthy cats. Acta Vet Scand. 2015;57(1):O14.

  38. Falkenö U, Hillström A, von Brömssen C, Strage EM. Biological variation of 20 analytes measured in serum from clinically healthy domestic cats. J Vet Diagn Invest. 2016;28(6):699-704.

  39. Scruggs JL, Flatland B, McCormick KA, Reed A. Biological variation of thromboelastography variables in ten clinically healthy horses. J Vet Emerg Crit. Care. 2016;26(1):80-84.

  40. Heilmann RM, Cranford SM, Ambrus A, Grützner N, Schellenberg S, Ruaux CG, Suchodolski JS, Steiner JM. Validation of an enzyme‐linked immunosorbent assay (ELISA) for the measurement of canine S100A12. Vet Clin Pathol. 2016; 45(1):135-147.

  41. Trumel C, Monzali C, Geffré A, Concordet DV, Hourqueig L, Braun J-PD, Bourgès-Abella NH. Hematologic and Biochemical Biologic Variation in Laboratory Cats. J Am Assoc Lab Anim Sci. 2016;55(5):503-509.

  42. Harris AN, Estrada AH, Gallagher AE, Winter B, Lamb KE, Bohannon M, Hanscom J, Mainville CA. Biologic variability of N-terminal pro-brain natriuretic peptide in adult healthy cats. J Feline Med Surg. 2017;19(2):216-223.

  43. Winter RL, Saunders AB, Gordon SG, Buch JS, Miller MW. Biologic variability of N-terminal pro-brain natriuretic peptide in healthy dogs and dogs with myxomatous mitral valve disease. J Vet Cardiol. 2017;19(2):124-131.

  44. Gal A, Weidgraaf K, Bowden J, Lopez‐Villalobos N, Cave N, Chambers J, Castillo‐Alcala, F. Biological Variability in Serum Cortisol Concentration Post‐adrenocorticotropic Hormone Stimulation in Healthy Dogs. J Vet Intern Med. 2017; 13(3):711-716.

  45. Winter RL, Saunders AB, Gordon SG, Miller MW, Fosgate GT, Suchodolski JS, Steiner JM. Biologic variability of cardiac troponin I in healthy dogs and dogs with different stages of myxomatous mitral valve disease using standard and high‐sensitivity immunoassays. Vet Clin Pathol. 2017; 46(2):299–307.

  46. Cohn-Urbach M, Ruaux CG, Nemanic S. Estimates of biologic variation in specific feline pancreatic lipase concentrations in cats without clinical or ultrasonographic evidence of pancreatitis. Vet Clin Pathol. 2017; 46(4):615-9.

  47. Heilmann RM, Grützner N, Handl S, Suchodolski JS, Steiner JM. Preanalytical validation of an in‐house radioimmunoassay for measuring calprotectin in feline specimens. Vet Clin Pathol. 2018; 47(1):100-7.

  48. Kopke MA, Burchell RK, Ruaux CG, Burton SE, Lopez‐Villalobos N, Gal A. Variability of symmetric dimethylarginine in apparently healthy dogs. J Vet Intern Med. 2018; 32(2):736-42.

    48a. Baral RM, Freeman KP. Variability of symmetric dimethylarginine in apparently healthy dogs. J Vet Intern Med. 2019; 33(1):7.

  49. Cuq B, Blois SL, Wood RD, Monteith G, Abrams‐Ogg AC, Bédard C, Wood GA. Reproducibility, stability, and biological variability of thrombin generation using calibrated automated thrombography in healthy dogs. Vet Clin Pathol. 2018; 47(2):218-26.

  50. Shropshire SB, Olver CS, Lappin MR. Variability of tissue factor‐activated thromboelastography and whole blood impedance platelet aggregometry in healthy dogs. J Vet Emerg Crit. Care. 2018; 28(4):334-9.

    50a. Baral RM, Freeman KP. Question relating to themethodology of a study evaluating thromboelastography and platelet aggregometry in healthy dogs. J Vet Emerg Crit. Care. 2019; EARLY VIEW

  51. Ilchyshyn NP, Villiers E, Monti P. Validation of a spectrophotometric method for GGT measurement in canine urine and determination of the urine GGT-to-creatinine ratio reference interval and biological variation in 41 healthy dogs. JJ Vet Diagn Invest. 2019; 31(1):33-9.

  52. Wright ME, Croser EL, Raidal S, Baral RM, Robinson W, Lievaart J, Freeman KP. Biological variation of routine haematology and biochemistry measurands in the horse. Equine veterinary journal. 2019; 51(3):384-90.

  53. Heilmann RM, Ruaux CG, Grützner N, Cranford SM, Bridges CS, Steiner JM. Biological variation of serum canine calprotectin concentrations as measured by ELISA in healthy dogs. Vet J. 2019: EARLY VIEW