Veterinary professional tool

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 & admission values

Enter pretreatment values where possible. Missing values stay unknown and are never silently treated as normal.

Units
Switches weight, glucose and urea/BUN conventions. Osmolality remains mOsm/kg and fluid volumes remain mL.
Species
Diabetes mellitus context
Use “known / supported” for established DM or compatible persistent hyperglycaemia with glucosuria and/or increased fructosamine. Stress hyperglycaemia alone does not confirm DM.
5% subtle · 8% obvious · 10–12% severe.
Optional. Used for the anion gap.
Optional. Affects total osmolality, not tonicity.
Optional comparison value. Classification always uses calculated effective osmolality: 2 × measured Na + glucose.
Interpret with pH and the anion gap.
Ketones — source
View current classification ↓

2 Correction targets

Set the sodium goal and deficit-replacement interval used by the fluid estimates.

Correct deficit over
Use a slower interval for hypertonicity or marked hypernatraemia.

3 Insulin protocol setup

These dose tables use regular (soluble/neutral) insulin. Do not substitute another product into the calculations.

Delivery protocol
Standard 250 mL. Pump rates recompute if changed.

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: effective osmolality = 2 × measured Na + glucose; total calculated osmolality = 2 × measured Na + glucose + urea (SI). The HHS flag uses effective osmolality >320 mOsm/kg and glucose >600 mg/dL. Corrected Na uses +1.6 mmol/L per 100 mg/dL glucose above 100 for the primary estimate; +2.4 is shown only as a secondary human-derived estimate. Anion gap = (Na + K) − (Cl + HCO₃). Formula choice and analyser intervals matter.

Clinical references: ALIVE 2026 companion-animal DKA consensus · iCatCare 2025 feline diabetes consensus · AAHA 2026 feline DKA guidance · Merck Veterinary Manual · 2024 canine sodium-correction study · canine BHB study · feline BHB study. Last clinically reviewed 19 August 2026.