ASK A VET™ · CLINICAL TOOLS

Diabetic Crisis Calculator — DKA vs HHS

Classify the crisis, then work through osmolality, corrected sodium, free water deficit, the fluid plan, safe correction rates, potassium and insulin — for dogs and cats.

By Dr Duncan Houston · For veterinary professional use

1 Patient & bloods

Enter what you have. Fields left blank are skipped in the relevant calculation.

Switches weight to lb and glucose/BUN to mg/dL; sodium, potassium and osmolality relabel to US units. Fluid volumes stay in mL.
Clinical estimate. 5% = subtle, 8% = obvious, 10–12% = severe/shocky.
Only affects total osmolality, not tonicity.
Normal <0.6 · monitor 0.6–3.0 · significant ketosis ≥3.0 (DKA risk). Most reliable ketone measure.

2 Correction targets

Slower (36–48 h) for HHS and marked hypernatraemia.

3 Insulin protocol

Regular (soluble) insulin only — Actrapid®, Humulin® R. Choose how you're delivering it.

Standard is 250 mL. Pump rates recompute to deliver the same dose if you change it.

A clinical tool from ASK A VET™ — Talk. Track. Trust.

For qualified veterinary use only. This calculator is decision support, not a substitute for clinical judgement, serial monitoring, or up-to-date references. Formulae assume adult patients and can behave unexpectedly at extreme values. Always re-check electrolytes, glucose and neurological status frequently, and adjust to the individual patient.

Method notes — Effective osmolality = 2·Na + glucose (mmol/L); total = 2·(Na+K) + glucose + urea. Corrected Na: Katz +1.6 and Hillier +2.4 mmol/L per 100 mg/dL (5.55 mmol/L) glucose above 100 mg/dL. Free water deficit = 0.6 × BW × (corrected Na ÷ target Na − 1). Na correction capped at 0.5 mmol/L/h (~10–12/24 h); glucose fall targeted 2.8–4.2 mmol/L/h. K⁺ sliding scale per Merck/DiBartola; KCl infusion ≤0.5 mmol/kg/h. Insulin CRI per Merck/DiBartola/Macintire — regular (soluble) insulin only, 2.2 U/kg dog / 1.1 U/kg cat into 250 mL 0.9% NaCl.

Copy the results

Auto-copy was blocked here. Select all and copy manually.