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Insulin, PZI (Protamine Zinc)

Prescription
Long-Acting Insulin
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
1 available
Interactions
1 documented
Formulations
1

Mechanism of action

Insulin complexed with excess protamine and zinc, forming large crystals that dissolve very slowly after SQ injection, providing prolonged basal insulin release. Longest duration of traditional insulins.

At a glance

Class
Long-Acting Insulin
Schedule
Prescription
Storage
Refrigerate 2–8°C; in-use at room temperature up to 60 days; gently roll before use; do not shake or freeze

Dosing

🐕

Dog

Not first-choice for dogs (NPH or Vetsulin preferred)
Dose
0.25–0.5 U/kg
Route
SQ
Frequency
q12h
🐈

Cat

FDA-approved (ProZinc) for feline diabetes
Dose
Route
SQ
Frequency
q12h
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 1

Strength

Storage

Refrigerate 2–8°C; in-use at room temperature up to 60 days; gently roll before use; do not shake or freeze

Safety

Monitoring parameters

Glucose curves q7–14 days initiallyFructosamine q2–4 weeksBody weightWater intake/urination
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

Major — 1

Prednisolone
major
Corticosteroid-induced insulin resistance destabilizes diabetic control in cats.
Management: Avoid if possible. If steroid needed (e.g., IBD in diabetic cat), monitor glucose intensively and adjust insulin dose. Budesonide may be preferred (less systemic effect).
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Brands

Other markets

ProZinc

FAQs

Frequently asked questions

What is Insulin, PZI (Protamine Zinc)?
Insulin, PZI (Protamine Zinc) is a long-acting insulin used in pets. Insulin complexed with excess protamine and zinc, forming large crystals that dissolve very slowly after SQ injection, providing prolonged basal insulin release. Longest duration of traditional insulins.
What is Insulin, PZI (Protamine Zinc) used for in pets?
Insulin, PZI (Protamine Zinc) is used in veterinary medicine for: Not first-choice for dogs (NPH or Vetsulin preferred); FDA-approved (ProZinc) for feline diabetes.
What is the Insulin, PZI (Protamine Zinc) dose for dogs?
For dogs, Insulin, PZI (Protamine Zinc) is typically dosed as follows — Not first-choice for dogs (NPH or Vetsulin preferred): 0.25–0.5 U/kg SQ q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Insulin, PZI (Protamine Zinc) dose for cats?
For cats, Insulin, PZI (Protamine Zinc) is typically dosed as follows — FDA-approved (ProZinc) for feline diabetes: undefined undefined SQ q12h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Insulin, PZI (Protamine Zinc) need a prescription?
Yes. Insulin, PZI (Protamine Zinc) is a prescription medication and should only be administered under veterinary supervision.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database
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