Veterinary Blood Gas Interpretation Calculator
Enter pH, PCO₂ and HCO₃ to identify the primary acid-base disturbance and whether compensation has begun.
pH
Normal 7.35–7.45
PCO₂ (mmHg)
Normal 35–45
HCO₃ (mEq/L)
Normal 20–26
Frequently asked questions
What is the difference between acidaemia and acidosis?
Acidaemia is a measured low pH (< 7.35). Acidosis is the underlying disturbance that causes it. A patient can have an acidosis (metabolic, say) but a normal pH if compensation has fully kicked in.
How do I know if compensation is appropriate?
Quick rule: for primary metabolic acidosis, expected PCO₂ ≈ 1.5 × HCO₃ + 8 (Winter's formula). If actual PCO₂ is significantly higher than expected, there's a concurrent respiratory acidosis. Similar formulas exist for the other disturbances.
Why does DKA show a high anion gap acidosis?
Ketone bodies (acetoacetate, β-hydroxybutyrate) are unmeasured anions. They replace HCO₃ on a 1:1 basis but aren't captured in routine chemistry, so the anion gap (Na - Cl - HCO₃) widens. Other high-anion-gap acidoses: lactic acidosis, ethylene glycol, severe uraemia.