Horse Side Vet Guide ®

Equine Health Resource

Blood, Electrolyte Levels



Electrolytes are elements or substances that become ions in solution. The balance of electrolytes in any animal’s body is critical to cellular function, thus survival.

Common electrolytes measured in the blood include sodium (Na), potassium (k+), and chloride. Calcium and phosphorus are less frequently measured.

Electrolytes are commonly monitored in very ill horses, especially those with intestinal and kidney diseases. Electrolyte losses can be very severe in these diseases.

Large quantities of electrolytes are lost in sweat.

Electrolyte levels are taken from a blood test. Electrolyte analyzers are common in veterinary hospitals today and electrolyte testing is considered a routine diagnostic and a helpful screening test. Electrolyte levels may be included in blood chemistries.


The determination of electrolyte concentrations using lab tests helps vets choose a treatment plan. The results of this test provide critical information in adjusting a treatment plan, particularly for very ill horses.


The sample must be processed quickly for accurate results for some electrolytes.

Electrolyte levels may be artificially raised or lowered by other substances in the blood. This must be considered when the results are interpreted.

Author: Doug Thal DVM Dipl. ABVP


We're not around right now. But you can send us an email and we'll get back to you, asap.