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Dog Insulin Dosage Calculator — AAHA Starting Dose for Diabetes

What starting insulin dose does your newly-diabetic pup need? This calculator applies the AAHA Diabetes Management Guidelines for Dogs & Cats to recommend a conservative starting dose for Vetsulin (porcine zinc), NPH (Humulin N, Novolin N), or Levemir (detemir). Dose titration after the first week must be done with your veterinarian using a glucose curve — never adjust insulin based on a single reading.

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Starting dose
3units per dose
Calculated: 3.4 U · Frequency: Every 12 hours (BID) with meals

Important syringe note

Vetsulin / Caninsulin is U-40 concentration. You MUST use U-40 syringes only. Using the wrong syringe causes accidental overdose or underdose.

AAHA first-choice. U-40 syringes required (NOT U-100).

This is a starting dose only. Your vet must confirm dose and adjust based on blood glucose curves (done after 1 week of the current dose). Never change dose without a veterinarian.

Vetsulin vs NPH vs Levemir: which insulin for canine diabetes?

InsulinTypeConcentrationStarting doseDuration
Vetsulin (porcine zinc)Veterinary-labeledU-400.25 U/kg q12h10-14 hr
Humulin N / Novolin N (NPH)Human insulinU-1000.25 U/kg q12h8-12 hr
Levemir (detemir)Human insulin analogU-1000.1 U/kg q12h14-24 hr
ProZinc (PZI)Veterinary-labeled (cats mainly)U-40Off-label dog use12-24 hr

Canine diabetes terminology

BG curve
Blood-glucose curve — readings taken every 1-2 hours after insulin to map peak/nadir; used by vets to titrate dose.
Nadir
Lowest BG point in the curve; should fall between 100-150 mg/dL for safe control.
U-40 vs U-100
Insulin concentration units per mL — Vetsulin/ProZinc are U-40; Humulin N, Novolin N, Levemir are U-100. Match syringe to insulin.
Somogyi rebound
Hyperglycemia caused by too much insulin, not too little — counterintuitive but common cause of "uncontrolled" diabetes.

Frequently Asked Questions

What is the starting insulin dose for a diabetic dog?

Per AAHA 2018 Diabetes Management Guidelines: Vetsulin or NPH at 0.25 U/kg every 12 hours, rounded to the nearest whole unit. Levemir (detemir) starts lower at 0.1 U/kg due to greater potency. A 20 kg dog on Vetsulin starts at 5 units twice daily.

What's the difference between U-40 and U-100 insulin?

U-40 = 40 units per mL (Vetsulin). U-100 = 100 units per mL (NPH, Levemir, most human insulins). Syringes are size-matched. Using a U-100 syringe with U-40 insulin gives 2.5× less insulin than intended — a critical dosing error.

How often should a diabetic dog get insulin?

Twice daily (every 12 hours) with meals. Skipping a dose is preferable to giving a late dose — hypoglycemia from overlapping doses is more dangerous than transient hyperglycemia.

How do I know if my dog's insulin is working?

Blood glucose curve (8-12 hourly BG readings over a dosing cycle) is the gold standard. Fructosamine blood test every 2-4 weeks also helps. Your vet should recheck after each dose change.

What are signs of low blood sugar (hypoglycemia)?

Weakness, confusion, stumbling, glazed eyes, seizures, collapse. If observed: rub Karo syrup/honey on the gums immediately and go to ER vet. Hypoglycemia from insulin overdose is a medical emergency.

Sources & References

  1. [1]
    AAHA 2018 Diabetes Management Guidelines — American Animal Hospital Association
  2. [2]
    Vetsulin Dosing Overview — Merck Animal Health
  3. [3]