Equis ISSN 2398-2977


Contributor(s): Graham Munroe, Vetstream Ltd


  • Definition: serum chloride concentration <99 mEq/l (99 mmol/l). 



  • Change in chloride concentration caused by: 
    • Loss of chloride ions.
    • Change in water balance (increase in free water). This is typically associated with a change in sodium concentration (hyponatremia   Hyponatremia  ).
  • Proportionally decreased chloride and sodium, or increased total body water relative to sodium and chloride:
  • Disproportionate decrease in serum chloride relative to sodium: 
    • Primary metabolic alkalosis (increased serum bicarbonate   →     decreased serum chloride), eg loss of plasma during exercise - sweating.
    • Respiratory acidosis compensatory response to increased serum bicarbonate in order to maintain electroneutrality.
    • Metabolic acidosis with an increased anion gap (AG), eg colic (lowered serum bicarbonate is counterbalanced by increase in other anions to maintain electroneutrality   →    serum chloride does not increase).
    • Diuretic therapy (thiazide and loop diuretics)   Therapeutics: cardiovascular system  , furosemide   Furosemide      →   loss of chloride via kidneys. 
    • Chronic respiratory acidosis   Acid-base imbalance  . 
  • Disproportionally decreased serum sodium and chloride relative to decrease in total body water:
  • Therapy with solution containing high sodium concentration relative to chloride:
    • Administration of sodium bicarbonate   Sodium bicarbonate  (very rare) (increased sodium bicarbonate    →   compensatory decreased sodium chloride).
    • High dose sodium penicillin  (very rare).
    • Hypochloremia may    →   alkalosis   →    increased potassium uptake   →    hyperkalemia.


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Schaer M (1999) Disorders of serum potassium, sodium, magnesium and chloride. J Vet Emerg Crit Care (4), 209-217 VetMedResource.

Other sources of information

  • Wingfield W E & Raffee M R (2002) Eds. The Veterinary ICU Book. Teton New Media, Jackson Hole, USA. 
  • Carlson G P (1997) Fluid, Electrolyte and Acid-base Balance. In: Clinical Biochemistry of Domestic Animals. 5th edn. Eds: Kameko J J, Harvey J W & Bruss M L. Academic Press, USA.