Vetdrugs 2.0Insulin is a peptide hormone supplied in short-, intermediate- and longer-acting preparations for treatment of diabetes mellitus and selected metabolic emergencies. Veterinary applications range from maintenance treatment of diabetic dogs and cats to management of diabetic ketoacidosis. Differences in molecular design, formulation and absorption produce distinct clinical time courses.
Group
Antidiabetic hormone
Mechanism of Action
Insulin binds its receptor tyrosine kinase and activates intracellular signaling that promotes glucose uptake in responsive tissues, glycogen synthesis and storage of metabolic substrates. It suppresses hepatic glucose production, lipolysis and ketone formation. Stimulation of cellular sodium–potassium ATPase moves potassium into cells. These effects explain its roles in diabetes, ketoacidosis and temporary correction of severe hyperkalemia.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Ketoacidosis with regular insulin | Reference only | IM | Dogs under 3 kg: initially 1 IU/animal, then 1 IU every hour. Dogs 3-10 kg: initially 2 IU/animal, then 1 IU hourly. Dogs over 10 kg: initially 0.25 IU/kg, then 0.1 IU/kg hourly; glucose-guided hospital protocol. | |
| NPH maintenance | Reference only | SC | Dogs under 15 kg: 1 IU/kg every 12-24 hours; dogs over 25 kg: 0.5 IU/kg every 12-24 hours. No 15-25 kg instruction is supplied. These are reported regimens rather than universal starting recommendations. | |
| Lente maintenance | Reference only | SC | Vetsulin initial 0.5 IU/kg once or twice daily; adjust with glucose monitoring, with changes commonly 25% of dose. | |
| PZI maintenance | Reference only | SC | Human recombinant PZI: start 0.5 IU/kg every 12 hours. In controlled patients the reported median was 0.9 IU/kg, range 0.4-1.5 IU/kg, every 12 hours. | |
| Glargine maintenance | Reference only | SC | Start 0.3 IU/kg every 12 hours, then titrate. Reported controlled-patient range 0.32-0.67 IU/kg every 12 hours. | |
| Detemir maintenance | Reference only | SC | 0.12-0.25 IU/kg every 12 hours; unusually potent in dogs. Accurate small-dose delivery may require a specific diluent. | |
| Regular-insulin ketoacidosis alternative | Reference only | IM | Initially 0.2 IU/kg, then 0.1 IU/kg hourly. Severe hypokalaemia may require a 25-50% lower initial amount. Aim for gradual glucose reduction; near 250 mg/dL, change to 0.1-0.3 IU/kg IM every 4-6 hours or, after rehydration, SC every 6-8 hours with dextrose support. | |
| Regular-insulin infusion preparation | Reference only | IV | Patient-specific mixture: add 2.2 IU/kg of regular insulin to 250 mL saline and prime the administration tubing with approximately 50 mL before connecting. Determine infusion rate from hourly glucose; the amount added is per kilogram, not 2.2 IU total. Use a separate insulin line. | |
| Hyperkalaemia insulin-dextrose treatment | Reference only | IV | Regular insulin 0.25-0.5 IU/kg slow IV with 50% dextrose at 4 mL per IU; alternative 0.5-1 IU/kg in fluids with 2 g dextrose per IU. Monitor glucose and potassium; this is a combined treatment. | |
| NPH or lente initial treatment | Reference only | SC | Separate initial regimen: 0.25 IU/kg every 12 hours of NPH human or porcine lente insulin; titrate by glucose monitoring. | |
| Glargine initial-treatment alternative | Reference only | SC | 0.25-0.5 IU/kg every 12 hours; formulation-specific alternative. | |
| Detemir initial-treatment alternative | Reference only | SC | 0.1-0.2 IU/kg every 12 hours; dogs are especially sensitive to detemir. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Ketoacidosis with regular insulin | Reference only | IM | 0.2 IU/kg initially, then 0.1 IU/kg hourly until glucose is below 300 mg/dL; subsequently 0.25-0.4 IU/kg SC every 6 hours with continuing monitoring. | |
| NPH maintenance | Reference only | SC | Not generally preferred because of short action. Reported alternatives: 0.25 IU/kg every 12 hours or 1-3 IU/cat every 12 hours. | |
| PZI maintenance | Reference only | SC | ProZinc: start 0.2-0.7 IU/kg every 12 hours or 1-2 IU/cat every 12 hours; titrate to response. Transition from Caninsulin is described at 0.5 IU/kg every 12 hours. A separate reported alternative begins at 0.5 IU/kg once or twice daily, usually twice, with subsequent doses usually no higher than 3 IU/cat; this is not a universal cap. | |
| Glargine maintenance | Reference only | SC | Start 0.5 IU/kg every 12 hours, then adjust. Some cats can be managed daily; twice daily is generally preferred. IM use for ketoacidosis is described without a complete separate numeric protocol. | |
| Detemir maintenance | Reference only | SC | Use the same initial schedule as the reported glargine protocol: 0.5 IU/kg every 12 hours, then glucose-guided titration. | |
| Regular insulin infusion | Reference only | IV | Reported guidance states 1.1-1.5 IU/kg/day, with a 250 mL saline bag at 10 mL/cat/hour, discarding the first 50 mL and replacing the bag at 24 hours. The preparation does not specify a consistent amount to add; retain as an incomplete protocol, not a mixing recipe. | |
| Lispro ketoacidosis infusion | Reference only | IV | Stated rate 0.09 IU/kg/hour conflicts with a fixed 2.2 IU per 250 mL mixture without a patient-specific fluid rate. Do not derive an automatic mixing protocol; monitor potassium. | |
| Regular-insulin ketoacidosis alternative | Reference only | IM | Initially 0.2 IU/kg, then 0.1 IU/kg hourly. Severe hypokalaemia may require a 25-50% lower initial amount. Aim for gradual glucose reduction; near 250 mg/dL, change to 0.1-0.3 IU/kg IM every 4-6 hours or, after rehydration, SC every 6-8 hours with dextrose support. | |
| Regular-insulin infusion preparation | Reference only | IV | Patient-specific mixture: add 2.2 IU/kg of regular insulin to 250 mL saline and prime the administration tubing with approximately 50 mL before connecting. Determine infusion rate from hourly glucose; the amount added is per kilogram, not 2.2 IU total. Use a separate insulin line. | |
| Hyperkalaemia insulin-dextrose treatment | Reference only | IM | Regular insulin 0.5-1 IU/kg IM plus IV dextrose at 2 g per IU; repeat only according to glucose and potassium response. | |
| Glargine ketoacidosis combination | Reference only | SC | Initially glargine 2 IU/cat SC plus 1 IU/cat IM; repeat SC every 12 hours. Repeat the IM amount no sooner than 4 hours later only if glucose remains above approximately 250-290 mg/dL; hospital glucose/electrolyte-guided protocol. | |
| Glargine detemir or PZI initial treatment | Reference only | SC | Use ideal body weight: glucose below 360 mg/dL, start 0.25 IU/kg every 12 hours; at or above 360 mg/dL, 0.5 IU/kg every 12 hours. Monitor closely for the first 3 days and adjust individually. An older conservative alternative is 1 IU/cat every 12 hours when early home monitoring is unavailable. | |
| Lente initial-treatment alternatives | Reference only | SC | Porcine lente: 0.5 IU/kg daily in one label regimen. Separate twice-daily alternatives use 1 IU/cat below 4 kg and 1.5-2 IU/cat above 4 kg, or 0.25-0.5 IU/kg according to presenting glucose. Do not combine alternatives or infer the unlisted exact 4 kg boundary. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Hyperkalaemia | Reference only | IV | Regular insulin 0.1-0.2 IU/kg/hour with dextrose. Example mixture: 50 IU regular insulin plus 500 mL of 50% dextrose in 5 L of fluids over 1 hour. This is an example mixture, not a universal weight-independent infusion. | |
| Diabetes mellitus PZI treatment | Reference only | IM, SC | PZI 0.15 IU/kg twice daily; true equine diabetes is uncommon and the cause of hyperglycaemia requires investigation. |
Birds
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Diabetes mellitus | Reference only | IM | NPH 0.067-3.3 IU/kg every 12-24 hours after stabilization. The initial regular-insulin amount 0.1-0.2 IU/kg has no route supplied. Obtain individual glucose curves; species response is highly variable. |
Ferrets
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Diabetes mellitus | Reference only | SC | NPH 0.5-1 IU/ferret twice daily, or the separate 0.1-0.5 IU/kg twice-daily starting regimen; adjust by glucose and ketones. | |
| Diabetes mellitus | Reference only | IM | NPH 0.1-0.5 IU/kg twice daily initially; titrate individually. |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Ketosis adjunct | Reference only | SC | PZI insulin 200 IU/animal every 48 hours; assess glucose and concurrent ketosis treatment. |
Indications
- Maintenance treatment of diabetes mellitus in dogs and cats using a suitable insulin formulation.
- Treatment of diabetic ketoacidosis and selected hyperosmolar diabetic emergencies within a complete metabolic and fluid-management plan.
- Temporary intracellular shifting of potassium in selected severe hyperkalemic emergencies, with glucose support as indicated.
- Treatment of diabetes mellitus in selected other veterinary species with an individualized formulation and regimen.
Contraindications
- Hypoglycaemia
- Inability to monitor blood glucose
Interactions
- Glucocorticoids oppose glucose-lowering action.
- Mixing regular with zinc-containing or other insulins can change absorption; do not mix formulations without a validated protocol.
Adverse effects
- Hypoglycaemia and hypokalaemia
- Injection discomfort, particularly with acidic glargine
Toxicity
Hypoglycaemia can cause weakness, seizures or coma. Measure glucose urgently and supply glucose while monitoring for recurrent hypoglycaemia.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Regular human insulin U-100 | Injection | 100 IU / mL | IV, IM, SC |
| NPH human insulin U-100 | Injection | 100 IU / mL | SC |
| Glargine U-100 | Injection | 100 IU / mL | SC |
| Detemir U-100 | Injection | 100 IU / mL | SC |
| Vetsulin porcine lente U-40 | Injection | 40 IU / mL | SC |
| ProZinc recombinant human PZI U-40 | Injection | 40 IU / mL | SC |
Monitoring and Administration
Use the syringe or device matching the exact insulin concentration: U-40 and U-100 are not interchangeable.
Monitor glucose curves or continuous glucose readings, clinical response and fructosamine. In ketoacidosis also follow electrolytes, hydration and ketone resolution.
Store as directed for the specific product; avoid freezing and heat. Resuspension instructions are formulation-specific; do not apply one mixing instruction to every insulin.
Do not use unvalidated compounded insulin. Dilution requires the formulation-specific diluent and controlled preparation.
Use only the insulin formulation named in the prescribed regimen; regular, NPH, lente, PZI, glargine, detemir and lispro are not interchangeable.
A 200 kg pony hyperlipaemia example alternates PZI 30 IU IM every 12 hours on odd days with 100 g oral glucose, and 15 IU every 12 hours on even days with 100 g oral galactose. This is a patient-specific calendar protocol, not a universal pony dose. Rotate injection sites and spell out insulin units to reduce transcription error.