ISSN 2398-2969      




  • Definition: serum chloride concentration >122 mEq/L.

    Normal ranges and abnormal values are dependent on equipment used and reference ranges established for that equipment.
  • Chloride ions constitute two thirds of the anions in the plasma and other components of the extracellular fluid.
  • Chloride is the major anion filtered by glomeruli and reabsorbed in the renal tubules.
  • Chloride ions play a role in determining osmolarity and acid base status.


Predisposing factors

  • Depends on the underlying cause.


  • Change in chloride concentration caused by:
    • Any gain of chloride.
    • Change in water balance (decrease in free water). This is always associated with a proportional increase or decrease in sodium Hypernatremia Hyponatremia.
  • Chloride should be corrected for changes in sodium (changes in water balance):
    [Cl] (corrected)= [Cl](measured) x [Na] (normal) / [Na] (measured)
  • Artifactual hyperchloremia (elevated measured [Cl-], with normal corrected [Cl-]) Blood biochemistry: chloride :
    • Pure water loss:
      • Diabetes insipidus Diabetes insipidus.
      • Essential hypernatremia Hypernatremia.
      • Increased ambient temperature.
      • Primary hypodipsia.
      • Fever.
      • Inadequate access to water.
    • Hypotonic fluid loss:
      • Osmotic diuresis.
      • Gastrointestinal (vomiting, diarrhea, intestinal obstruction).
      • Renal (osmotic diuresis, chronic renal failure, acute renal failure, post-obstructive diuresis).
      • Third spacing.
      • Cutaneous losses.
  • Corrected hyperchloremia (associated with hyperchloremic [normal AG] metabolic acidosis Acid base imbalance ):
    • Pseudo hyperchloremia:
      • Lipemic sample (evaluated with colorimetric technique).
      • Therapy with potassium bromide Potassium bromide (bromide is measured as chloride in every chloride assay).
    • Excessive loss of sodium relative to chloride:
      • Diarrhea associated with gastrointestinal loss of sodium rich/chloride poor fluid.
    • Renal chloride retention:
      • Diarrhea.
      • Renal failure Kidney: chronic kidney disease (CKD) Kidney: acute kidney injury (AKI).
      • Type I renal tubular acidosis (renal tubular disorders that cause renal wasting of bicarbonate or low hydrogen ion secretion).
      • Diabetes mellitus Diabetes mellitus (in the initial or resolving phase when ketones are eliminated in urine as fast as they are generated: excretion of ketones in the urine in place of chloride).
      • Chronic respiratory alkalosis.
      • Drug induced (spironolactone Spironolactone
      • inhibits sodium reabsorption and increase chloride retention; acetazolamide Acetazolamide ).
    • Excessive gain of chloride relative to sodium:


This article is available in full to registered subscribers

Sign up now to start a free trial to access all Vetlexicon articles, images, sounds and videos, or Login


This article is available in full to registered subscribers

Sign up now to start a free trial to access all Vetlexicon articles, images, sounds and videos, or Login

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Biondo A W & De Morais H A (2008) Chloride a quick reference. Vet Clin Small Animal Practice 38 (3), 459-46 PubMed.
  • Schaer M (1999) Disorders of serum potassium, sodium, magnesium and chloride. J Vet Emerg Crit Care (4), 209-217 VetMedResource.
  • De Morais H A (1992) Chloride ion in small animal practice: the forgotten ion. J Vet Emerg Crit Care 2 (1), 11-24 VetMedResource.

Other sources of information

  • Small Animal Critical Care Medicine (2008) Eds D C Silverstein and K Hopper. Saunders Elsevier, St Louis, Missouri.
  • Fluid, Electrolytes and Acid-base Disorders in Small Animal Practice (2006) Eds S P DiBartola, Saunders Elsevier, St Louis Missouri.
  • The Veterinary ICU Book (2002) Eds W E Wingfield and M R Raffee. Teton New Media, Jackson Hole, WY.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!


To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code