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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

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

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).

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.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
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 →