Dog Insulin Calculator
Educational canine insulin reference. Shows commonly cited weight-based starting dose ranges for dogs with diabetes. This is not a veterinary prescription.
🐾 Canine Insulin Reference Estimator
Shows the commonly cited starting dose range only. Your veterinarian must prescribe the actual dose for your dog.
Canine Starting Dose Reference
IU per dose
IU per dose
IU per dose
(vet-prescribed)
Vetsulin and Caninsulin are U-40 (40 IU/mL). Most human insulins are U-100 (100 IU/mL). Using a U-100 syringe with U-40 insulin (or vice versa) will result in a 2.5× overdose or underdose — potentially fatal. Always use the syringe type that matches your insulin concentration exactly, as instructed by your veterinarian.
Understanding Canine Insulin Dosing
Vet Diagnosis First
Canine diabetes requires a veterinary diagnosis — confirmed blood glucose and urine glucose testing. Never start insulin without a confirmed diagnosis.
Vet Prescribes Dose
Your vet determines the starting dose based on your dog's specific blood glucose, weight, health status, and food intake.
Glucose Curves
Dose adjustment uses glucose curves — measurements taken over 12–24 hours. Your vet may do this in clinic or train you to monitor at home.
Consistent Feeding
Dogs with diabetes should eat consistent meals at consistent times, matched to insulin injections. Diet changes can significantly affect dose requirements.
Syringe Type Matters
Vetsulin is U-40 — use U-40 syringes only. Using the wrong syringe type causes severe dosing errors. Ask your vet which syringe to use.
Know Emergency Signs
Weakness, trembling, glazed eyes, or collapse can indicate hypoglycemia. Rub sugar on gums and call your vet immediately.
Canine Diabetes: Key Differences From Human Diabetes
Canine diabetes mellitus most closely resembles Type 1 diabetes in humans — most dogs require lifelong insulin therapy because their pancreatic beta-cell function is severely impaired or absent. Unlike human Type 2 diabetes, oral hypoglycemic agents are generally not effective in dogs, and insulin is required in virtually all cases.
Commonly Cited Starting Dose Range (Vetsulin / Lente)
Source: Vetsulin prescribing information; Feldman & Nelson, Canine and Feline Endocrinology and Reproduction, 4th ed. Many vets start at the conservative low end (0.25 IU/kg) to minimise hypoglycemia risk, then titrate up based on glucose curves. Maximum starting dose is typically 8–10 IU per injection regardless of weight.
Why Canine Dosing Requires Individual Veterinary Assessment
- Blood glucose at diagnosis varies widely and affects initial dose
- Concurrent conditions (urinary tract infection — very common in diabetic dogs, Cushing's disease, hypothyroidism) can dramatically alter insulin requirements
- Diet content (carbohydrate amount, feeding schedule) directly interacts with insulin timing and dose
- Intact females have marked insulin resistance driven by progesterone, especially during diestrus — spaying is often recommended to improve glycemic stability
- Individual dogs vary enormously in insulin sensitivity — two same-weight dogs may need very different doses
U-40 vs U-100: Critical Concentration Warning
If your dog is on Vetsulin (U-40) and you use a standard U-100 human insulin syringe, you will inject 2.5× the intended dose — potentially causing fatal hypoglycemia. Always use the syringe size that matches your insulin concentration. Your vet will prescribe the correct syringe.
Sources & References
- Vetsulin (porcine insulin zinc suspension) Prescribing Information. Merck Animal Health. Link
- Feldman EC, Nelson RW, Reusch C, Scott-Moncrieff JC. Canine and Feline Endocrinology. 4th ed. Elsevier; 2015. Chapter 11: Canine Diabetes Mellitus.
- American Animal Hospital Association (AAHA). Diabetes Management Guidelines for Dogs and Cats. 2018. Link
Last reviewed: June 2025
Frequently Asked Questions
What insulin is used for diabetic dogs?
The most commonly prescribed insulin for dogs in the US is Vetsulin (porcine lente insulin, U-40), which is FDA-approved for canine diabetes. Some vets use Caninsulin (lente, U-40, used outside the US), NPH (Humulin N, Novolin N, U-100), or in some cases glargine. The choice of insulin, concentration, and syringe type must be determined by your veterinarian — never substitute insulin types without guidance. Using the wrong concentration or syringe can cause a fatal dosing error.
What is the starting insulin dose for a diabetic dog?
A commonly cited starting range is 0.25–0.5 IU/kg twice daily (BID). For a 20 kg dog, this suggests 5–10 IU per injection. However, the actual starting dose must always be set by a veterinarian based on blood glucose at diagnosis, weight, diet, and health assessment. Many vets start at the conservative low end (0.25 IU/kg) to minimise hypoglycemia risk and titrate up based on glucose curves. Never give your dog insulin without a vet's prescription.
How do I know if my dog's insulin dose needs adjusting?
Dose adjustment is guided by glucose curves — serial blood glucose measurements over 12–24 hours. Your vet will advise on the monitoring method (in-clinic or at-home). Signs that the dose may need review include persistent hyperglycemia symptoms (excess thirst, frequent urination, weight loss, cloudy lens/cataracts) or hypoglycemia signs (weakness, trembling, disorientation, collapse). Never adjust your dog's dose without veterinary guidance.
What are the signs of hypoglycemia in dogs?
Signs of low blood sugar in dogs include weakness, wobbliness, trembling, disorientation, glazed eyes, seizures, or collapse. If you observe these signs in a diabetic dog: rub Karo syrup or honey on the gums immediately and contact your veterinarian or emergency animal hospital. Do not give another dose of insulin. Severe hypoglycemia in dogs is a veterinary emergency — time matters.
Can cats use the same calculator as dogs?
No. Cats and dogs have very different insulin responses and are treated with different protocols. Cats are more commonly treated with long-acting insulin analogs (glargine or detemir) rather than lente, and the dosing approach differs significantly. Feline diabetes can sometimes go into remission with early, aggressive treatment — a critical difference from canine diabetes. Never use a dog insulin calculator for a cat. Feline diabetes management requires species-specific veterinary guidance.