Cat Owners

Frequently Asked Questions

Get answers to many of the questions pet owners have about feline diabetes, and at home treatment with PROZINC® (protamine zinc recombinant human insulin).

Looking for more information? Check out our videos, downloadable guides and other free resources.

Feline Diabetes

Diabetes mellitus occurs when a cat’s body isn’t producing enough insulin, or stops responding effectively to insulin. Most often, cats are diagnosed with Type II diabetes, meaning their bodies stop responding properly to insulin in the bloodstream. The most common signs of feline diabetes are increased thirst, urination, appetite, and weight loss, even with increased food intake.

Unfortunately, no. Once diagnosed, a cat will always be considered diabetic. The good news is, feline diabetes can be easily controlled at home with the right treatment. In some cases, cats with diabetes may go into remission, meaning they neither exhibit the clinical signs nor do they require insulin injections. However, these patients should still be considered diabetic because remission is not always permanent and signs  could return.

The signs of diabetes occur because of persistently high blood glucose levels (hyperglycemia). Most often, cat owners notice excessive thirst and urination, increased appetite and weight loss.

Often, if a cat’s blood glucose is persistently elevated, they will experience hyperglycemia. Signs  of hyperglycemia include increased thirst, urination and appetite. 

If your cat’s glucose level drops too low, your cat may exhibit signs  of hypoglycemia (low blood glucose). These include lethargy, sluggishness, trembling and seizures. Hypoglycemia with clinical signs is a medical emergency that requires immediate veterinary intervention.

If your cat is experiencing hyperglycemia, it means his/her blood glucose level is too high. After blood glucose stabilizes with treatment, it may occasionally rise due to stress, illness, injury or changes to the cat’s normal routine (such as ingesting something unusual or missing a PROZINC injection).


Signs  of hyperglycemia include:

  • Excessive thirst

  • Excessive urination

  • Increased appetite

  • Lethargy


To help avoid hyperglycemia, maintain a routine. Be consistent by feeding and giving PROZINC injections at the same times each day. Try to keep your cat out of stressful situations, which can cause blood glucose levels to spike.

If you suspect hyperglycemia, contact your veterinarian right away.

If your cat is experiencing hypoglycemia, it means his/her blood glucose level is too low. Hypoglycemia may be dangerous and potentially life threatening. It can occur if a cat has received too much insulin, not eaten enough, and/or experienced strenuous activity. Educating yourself about hypoglycemia is the first step to avoiding it.

Signs of hypoglycemia include:
· Weakness
· Depression
· Staggering or trouble walking
· Unusual behavior
· Muscle twitching
· Seizure
· Coma

To avoid hypoglycemia, be sure to give your cat the correct dose of PROZINC, stick to a feeding and treatment schedule and visit your veterinarian regularly to monitor treatment progress.

If you suspect hypoglycemia, don’t panic. Here’s what you can do:
· If your cat is unconscious, rub a tablespoon of corn syrup or honey on the gums and contact your veterinarian immediately
· If your cat remains unconscious and/or has a seizure, take it to the vet immediately
· If your cat is conscious , hand-feed 1 tablespoonful of corn syrup or honey until your cat is alert enough to eat normal food

Remember that hypoglycemia is a medical emergency that requires immediate action.


PROZINC is a sterile, aqueous suspension of protamine zinc recombinant human insulin indicated for the reduction of hyperglycemia and associated clinical symptoms or signs in cats with diabetes mellitus.1 It is the only insulin that is both FDA-approved and recommended by the American Animal Hospital Association (AAHA) for diabetic cats.

PROZINC, like other insulin, helps regulate cellular metabolism, in part by facilitating glucose uptake into cells of the heart, bone and fat tissue, and helping these cells and other cells in the body use glucose for energy.2

Visit our How PROZINC Helps page to learn more.

PROZINC is the first and only insulin that is both FDA-approved and recommended by the American Animal Hospital Association (AAHA) for diabetic cats. PROZINC is designed for cats and backed by the largest safety and efficacy study to date.3

Learn More about PROZINC.

PROZINC should be mixed by gently rolling the vial before withdrawing the dose prescribed by your veterinarian from the vial. Using a U-40 syringe, administer the injection under the skin along the back of the neck or on the side of the cat.1 


NOTE: It is important that you roll the vial and not shake it. Shaking the vial may reduce the effectiveness of the insulin by breaking the insulin molecules apart.


Watch our step-by-step videos on administering PROZINC to cats.

PROZINC is supplied as a sterile injectable suspension in 10-mL multidose vials. Each mL of PROZINC product contains 40 IU (international units) of recombinant human insulin.

Store in an upright position in the refrigerator at 36-46 degrees F (2-8 degrees C). Do not freeze it and protect it from light.1

PROZINC is a suspension and once mixed has a whitish cloudy appearance. If discoloration or other abnormal appearances are observed, indicating contamination within the vial, it should be discarded. Loss of insulin activity in the bottle should always be considered whenever clinical signs recur, regardless of the amount of insulin in the bottle.4

PROZINC carries a two-year shelf life from the date of manufacture5, and is safe to use within 60 days of opening.

Use of a syringe other than a U-40 syringe may result in incorrect dosing. Read our Safety and Dosing information to learn more.

Cat owners should contact their regular veterinarian. Veterinarians and veterinary professionals are encouraged to call Boehringer Ingelheim Veterinary Technical Support Team (VeTS) at 1-866-638-2226 for product inquiries. 


To report a suspected adverse reaction to PROZINC, please call 1-866-638-2226.

The safety and effectiveness of PROZINC insulin in kittens and in breeding, pregnant and lactating cats has not been evaluated.

Accidental injection may cause hypoglycemia. In case of accidental injection, seek medical attention immediately. Exposure to product may induce a local or systemic allergic reaction in sensitized individuals.  


PROZINC, like other drugs, may cause side effects. Serious side effects can occur with or without warning. 

Please contact your veterinarian immediately if you think your cat has a medical problem or side effect from PROZINC therapy. 

The most common insulin-related side effect is low blood sugar (hypoglycemia). Signs of low blood sugar (hypoglycemia) can occur suddenly and may include: 

  • Weakness
  • Staggering gait
  • Muscle twitching 
  • Coma 
  • Depression, lethargy, sluggishness 
  • Behavioral changes 
  • Seizures, convulsions 
  • Death

It is recommended that PROZINC be administered twice daily, 12 hours apart, to ensure all-day control.


As with any medication, you should administer PROZINC as prescribed by your veterinarian. Contact your veterinarian before making any adjustments to your cat’s treatment.

Each cat will respond differently, but based on the results of a field effectiveness study, 76% of the cats enrolled in the study were considered a treatment success by 45 days.1,6

Obesity is common in diabetic cats and causes reversible insulin resistance, which can correct itself when weight is lost. Research also suggests that diabetic cats may be predisposed to developing higher post-meal blood glucose levels after eating a high-carbohydrate meal.


Ultimately, your veterinarian should determine your cat’s treatment, and will recommend special diets as needed.

Important User Safety Information: For use in dogs and cats only. Keep out of the reach of children. Avoid contact with eyes. In case of contact, immediately flush eyes with running water for at least 15 minutes. Accidental injection may cause hypoglycemia. In case of accidental injection, seek medical attention immediately. Exposure to product may induce a local or systemic allergic reaction in sensitized individuals.

1 PROZINC product insert.

2 Plumb DC. Plumb’s Veterinary Drug Handbook. 5th ed. Hoboken, NJ: Wiley-Blackwell;

3 Nelson RW, Henley K, Cole C, et al. Field safety and efficacy of protamine
zinc recombinant human insulin for treatment of diabetes mellitus in cats.
J Vet Intern Med. 2009; 23:787-793.

4 Ettinger SJ, Feldman EC. Textbook of Veterinary Internal Medicine. 6th ed. Vol 2. Philadelphia,  
PA: WB Saunders; 2004:1790-1791.

5 PROZINC® (protamine zinc recombinant human insulin) [Freedom of Information Summary]. St. Joseph, MO: Boehringer Ingelheim Vetmedica, Inc; 2009.