• 1
    Henderson LJ. The theory of neutrality regulation in the animal organism. Am J Physiol 1908;21:427428.
  • 2
    Hasselbalch KA. Die Berechnung der Wasserstoffzahl des Blutes aus der freien und gebundenen Kohlensäure desselben, und die Sauerstoffbindung des Blutes als Funktion der Wasserstoffzahl. Biochem Z 1916;78:112144.
  • 3
    Constable PD. Clinical assessment of acid-base status. Strong ion difference theory. Vet Clin North Am Food Anim Pract 1999;15:447471.
  • 4
    Constable PD. Clinical assessment of acid-base status: Comparison of the Henderson-Hasselbalch and strong-ion approaches. Vet Clin Pathol 2000;29:115128.
  • 5
    Constable PD, Streeter RK, Koenig GR, et al. Determinants and utility of the anion gap in predicting hyperlactatemia in cattle. J Vet Intern Med 1997;11:7179.
  • 6
    Constable PD, Hinchcliff KW, Muir WW. Comparison of anion gap and strong ion gap as predictors of unmeasured strong ion concentration in plasma and serum from horses. Am J Vet Res 1998;59:881887.
  • 7
    Constable PD, Stämpfli HR, Navetat H, et al. Use of a quantitative strong ion approach to determine the mechanism for acid-base abnormalities in sick calves with or without diarrhea. J Vet Intern Med 2005;19:581589.
  • 8
    Stewart PA. Independent and dependent variables of acid-base control. Resp Physiol 1978;33:926.
  • 9
    Stewart PA. How to approach acid base. 1981. Available at:, accessed March 14, 2012.
  • 10
    Stewart PA. Modern quantitative acid–base chemistry. Can J Physiol Pharmacol 1983;61:14441461.
  • 11
    Constable PD. A simplified strong ion model for acid base equilibria: Application to horse plasma. J Appl Physiol 1997;83:297311.
  • 12
    Constable PD. Calculation of variables describing plasma nonvolatile weak acids for use in the strong ion approach to acid-base balance in cattle. Am J Vet Res 2002;63:482490.
  • 13
    Kellum JA. Clinical review: Reunification of acid-base physiology. Crit Care 2005;9:500507.
  • 14
    Siggaard-Andersen O, Fogh-Andersen N. Base excess or buffer base (strong ion difference) as measure of a non-respiratory acid-base disturbance. Acta Anaesth Scand Suppl 1995;107:123128.
  • 15
    Kurtz I, Kraut J, Ornelian V, Nguyen MK. Acid-base analysis: A critique of the Stewart and bicarbonate-centered approaches. Am J Physiol–Renal Physiol 2008;294:F1009F1031.
  • 16
    de Morais H, Constable PD. Strong ion approach to acid-base disorders. In: DiBartola SP, ed. Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice. 3rd ed. Philadelphia, PA: W.B. Saunders Company; 2006:310321.
  • 17
    Siegling-Vlitakis C, Kohn B, Kellermeier C, et al. Qualification of the Stewart variables for the assessment of the acid-base status in healthy dogs and dogs with different diseases. Berl Münch Tierärztl Wschr 2007;120:148155.
  • 18
    Bachmann L, Homeier T, Arlt S, et al. Influence of different oral rehydration solutions on abomasal conditions and the acid-base status of suckling calves. J Dairy Sci 2009;92:16491659.
  • 19
    Elkhair N, Siegling-Vlitakis C, Radtke E, et al. Age-dependent response of the acid-base parameters (Henderson-Hasselbalch, Stewart) in healthy calves with experimentally induced metabolic acidosis. Berl Münch Tierärztl Wschr 2009;122:6369.
  • 20
    Reinhold P, Hartmann H, Constable PD. Characterization of acid-base abnormalities in pigs experimentally infected with Chlamydia suis. Vet J 2010;184:212218.
  • 21
    Viu J, Jose-Cunilleras E, Armengou L, et al. Acid-base imbalances during a 120 km endurance race compared by traditional and simplified strong ion difference methods. Equine Vet J Suppl 2010;42Suppl 38:7682. evj_213 76.82
  • 22
    Berchtold J. Intravenous fluid therapy of calves. Vet Clin North Am Food Anim Pract 1999;15:505531.
  • 23
    Naylor JM. Oral fluid therapy in neonatal ruminants and swine. Vet Clin North Am Food Anim Pract 1990;6:5167.
  • 24
    Nappert G, Zello GA, Naylor JM. Oral rehydration therapy for diarrheic calves. Compend Contin Educ Pract Vet (Food Animal Practice) 1997;19:S181S190.
  • 25
    Navetat H, Biron P, Contrepois M, et al. Les gastroentérites paralysantes: Maladie ou syndrome? Bull Acad Vet de France 1997;70:327336.
  • 26
    Schelcher F, Marcillaud S, Braun JP, et al. Metabolic acidosis without dehydration and no or minimal diarrhoea in suckler calves is caused by hyper D-lactatemia. Proceedings of the World Buiatric Congress, Sydney, Australia, 1998;371374.
  • 27
    Omole OO, Nappert G, Naylor JM, Zello GA. Both L- and D-lactate contribute to metabolic acidosis in diarrheic calves. J Nutr 2001;131:21282131.
  • 28
    Ewaschuk JB, Naylor JM, Zello GA. Anion gap correlates with serum D- and DL-lactate concentrations in diarrheic calves. J Vet Intern Med 2003;17:940942.
  • 29
    Ewaschuk JB, Naylor JM, Palmer R, et al. D-lactate production and excretion in diarrheic calves. J Vet Intern Med 2004;18:744747.
  • 30
    Abeysekara S, Naylor JM, Wassef AW, et al. D-lactic acid-induced neurotoxicity in a calf model. Am J Physiol Endocrinol Metab 2007;293:E558E565.
  • 31
    Gentile A, Sconza S, Lorenz I, et al. D-lactic acidosis in calves as a consequence of experimentally induced ruminal acidosis. J Vet Med A Physiol Pathol Clin Med 2004;51:6470.
  • 32
    Lorenz I, Gentile A, Klee W. Investigations of D-lactate metabolism and the clinical signs of D-lactataemia in calves. Vet Rec 2005;156:412415.
  • 33
    Gentile A, Lorenz I, Sconza S, Klee W. Experimentally induced systemic hyperchloremic acidosis in calves. J Vet Intern Med 2008;22:190195.
  • 34
    Lorenz I. D-lactic acidosis in calves. Vet J 2009;179:197203.
  • 35
    Kasari T, Naylor J. Clinical evaluation of sodium bicarbonate, sodium L-lactate and sodium acetate for the treatment of acidosis in diarrheic calves. J Am Vet Med Assoc 1985;187:392397.
  • 36
    Naylor J, Forsyth G. The alkalinizing effects of metabolizable bases in the healthy calf. Can J Vet Res 1986;50:509516.
  • 37
    Constable PD. Fluids and electrolytes. In: Brumbaugh GW, guest ed. Clinical Pharmacology. Vet Clin North Am Food Anim Pract. Philadelphia, PA: W.B. Saunders Company; 2003;19:140.
  • 38
    Hartsfield SM. Sodium bicarbonate and bicarbonate precursors for treatment of metabolic acidosis. J Am Vet Med Assoc 1981;179:914916.
  • 39
    Robergs RA, Ghiasvand F, Parker D. Biochemistry of exercise-induced metabolic acidosis. Am J Physiol Regul Integr Comp Physiol 2004;287:R502R516.
  • 40
    Constable PD. Hyperchloremic acidosis: The classic example of strong ion acidosis. Anesth Analg 2003;96:919922.
  • 41
    Constable PD. In response: Letters to the editor. Anesth Analg 2004;98:271272.
  • 42
    Constable PD. Iatrogenic hyperchloremic acidosis due to large volume fluid administration: Mechanism, diagnosis, and management. Int J Intens Care 2005;12:111122.
  • 43
    Constable PD. Strong ion difference theory: A revolutionary approach to the diagnosis and treatment of acid-base abnormalities in cattle. Hungarian Vet J 2008;130 Suppl 1. Keynote lectures:2833.
  • 44
    Deetjen P, Lichtwarck-Aschoff M. Säure-Base-Haushalt aus der Perspektive von P. Stewart. Anaesthesist 2007;56:11851199.
  • 45
    Stämpfli HR, Pringle JH, Lumsden JH, et al. Experimental evaluation of a novel oral electrolyte solution in the treatment of natural occurring neonatal calf diarrhoea. Proceedings of the XIXth World Buaitrics Congress, Edinburgh, Scotland, U.K, 1996, 98101, British Cattle Association, Edinburgh, Scotland, UK, 1996.
  • 46
    Constable PD, Gruenberg W, Carstensen L. Comparative effects of two oral rehydration solutions on milk clotting, abomasal luminal pH, and abomasal emptying rate in suckling calves. J Dairy Sci 2009;92:296312.
  • 47
    Annison EF, White RR. Formate metabolism in sheep. Biochem J 1962;84:552557.
  • 48
    Hanzlik RP, Fowler SC, Eells JT. Absorption and elimination of formate following oral administration of calcium formate in female human subjects. Drug Metab Dispos 2005;33:282286.
  • 49
    Berchtold JF. Investigation on the diagnosis and treatment of systemic acidosis in calves. Diss. Med. Vet., Free University of Berlin; 1998.
  • 50
    Sen I, Altunok V, Ok M, et al. Efficacy of oral rehydration therapy solutions containing sodium bicarbonate or sodium acetate for treatment of calves with naturally acquired diarrhea, moderate dehydration, and strong ion acidosis. J Am Vet Med Assoc 2009;234:926934.
  • 51
    Kirkendol P, Starrs J, Gonzalez F. The effects of acetate, lactate, succinate and gluconate on plasma pH and electrolytes in dogs. Trans Am Soc Artif Intern Organs 1980;26:323327.
  • 52
    Stetten MR, Topper YJ. Pathways from gluconic acid to glucose in vivo. J Biol Chem 1953;203:653664.
  • 53
    CLSI. Blood Gas and pH Analysis and Related Measurements; Approved Guidelines. 2nd edition. CLSI document C46-A2. Wayne, PA: Clinical and Laboratory Standards Institute; 2009.
  • 54
    van Beaumont W, Greenleaf JE, Juhos L. Disproportional changes in hematocrit, plasma volume, and proteins during exercise and bed rest. J Appl Physiol 1972;33:5561.
  • 55
    Fischer W, Butte R. Vergleichende untersuchungen des elektrolyt- und blutstatus bei gesunden und an enteritis erkrankten kälbern. (1. Mitteilung). Dtsch Tierärztl Wschr 1974;81:567570.
  • 56
    Berchtold JF, Constable PD, Smith GW, et al. Effects of intravenous hyperosmotic sodium bicarbonate on arterial and cerebrospinal fluid acid-base status and cardiovascular function in calves with experimentally induced respiratory and strong ion acidosis. J Vet Intern Med 2005;19:240251.
  • 57
    Koch A, Kaske M. Clinical efficacy of intravenous hypertonic saline solution or hypertonic bicarbonate solution in the treatment of inappetent calves with neonatal diarrhea. J Vet Intern Med 2008;22:202211.
  • 58
    Liskaser F, Bellomo R, Hayhoe M, et al. Role of pump prime in the etiology and pathogenesis of cardiopulmonary bypass–associated acidosis. Anesthesiology 2000;93:11701173.
  • 59
    Radostits OM, Gay CC, Hinchcliff KW, Constable PD. Reference laboratory values. Appendix 2. In: Radostits OM, Gay CC, Hinchcliff KW, Constable PD, eds. Veterinary Medicine. A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goats. 10th ed. Philadelphia, PA: W.B. Saunders Company; 2007: 20472050.