Clinical judgment required. This calculator is a decision-support tool, not a substitute for veterinary consultation.

Fractional Excretion of ElectrolytesCanineFeline

Calculate fractional excretion (FE) of electrolytes for dogs and cats. Measures the percentage of a filtered electrolyte that is excreted in urine: FE = (Urine_X × Plasma_Cr) / (Plasma_X × Urine_Cr) × 100. Supports sodium (FENa), potassium (FEK), chloride (FECl), and phosphorus (FEPO4). FENa is used to differentiate prerenal azotemia (low FENa) from intrinsic renal disease (high FENa). Used for acute kidney injury assessment, renal tubular function evaluation, electrolyte imbalance workup, chronic kidney disease monitoring, and differentiating pre-renal from renal azotemia. Common queries: 'fractional excretion of sodium in a dog' or 'FENa for kidney disease'.

Species

Electrolyte

Urine Electrolyte Concentration

mEq/L

Plasma Electrolyte Concentration

mEq/L

Urine Creatinine

mg/dL

Plasma Creatinine

mg/dL

Fractional Excretion

—%