Vetsulin is Back!

By Dr . Joi Sutton|2017-11-28T16:14:35-05:00Updated: May 9th, 2013|Pet Care, Pet Diabetes, Pet Newsletter|12 Comments

There has been buzz on the vet street for months that Vetsulin is coming back. Well, the time is now here. Merck just brought back this porcine insulin zinc suspension after a lapse on the American market since 2009.

This is good news to pets that did well on this product, and it gives veterinarians another choice of insulin for diabetic pets, particularly dogs.

Vetsulin never left the European nor Canadian markets. It went by the name Caninsulin outside the USA. In 2009 the FDA raised concerns about predictability and onset of action with Vetsulin. In 2010 the product was only allowed for critical needs patients (those who couldn’t be managed on other insulins based on a veterinarian’s discretion). Merck discontinued production of Vetsulin in 2011. The issues have been resolved and Vetsulin is back on the American market.

What does this mean to you? That depends. If your pet is well-regulated on whichever insulin your veterinarian has chosen for your pet, it means nothing. However, if you are one of the diabetic dog owners whose pet did better on Vetsulin but had to switch to another insulin such as NPH or Demetir when Vetsulin became unavailable, it might be an option to switch back.

In over 20 years of veterinary practice I’ve seen products come and go. There is nothing quite as frustrating as getting your pet on just the right dose of insulin and having the insulin go off the market. This happened many years ago with PZI and again in 2009 with Vetsulin. It’s kind of like working on a spreadsheet for hours, thinking you are saving it periodically, only to close it out and find that it has disappeared. The difference is that regulating your pet’s diabetes it is far more dear. Your pet is your family, your sidekick, your best friend, your little buddy. Changing from one insulin at whatever dose to another does NOT mean you will use the same unit dosage of a different insulin. Different insulins have different strengths. One pet may absorb it differently than another. Duration of action for a particular insulin can be quite variable from pet to pet – this is why we do insulin curves.

One of the theoretical benefits to Vetsulin is that it is porcine (pork) based. Dog insulin and pork insulin are structurally similar, so the small risk of forming antibodies to the insulin is lessened. Additionally, some believe that pork insulin works better for dogs due to the similarity in molecules. Along the same lines cat insulin is structurally similar to beef insulin. Humulin insulins and glargine/Lantus are human recombinant products. If only we vets had a crystal ball to tell us which would be the best choice for each individual pet! The truth of the matter is that some pets do better on one type of insulin than another. Which insulin is best for your pet is for you and your veterinarian to decide based on glucose curves.

Remember to always check the concentration of the insulin and match the syringe to that insulin. Vetsulin is U-40, meaning that there are 40 units of insulin per cubic centimeter or milliliter. Many insulins are U-100, meaning that there are 100 units of insulin per cc or ml. Using U-100 syringes with a U-40 insulin could result in overdosing your pet. Although there are conversion tables that can be found on the internet, I strongly advise against using a U-100 syringe with a U-40 product. One little math error can have dire consequences. Use a syringe that matches the insulin concentration.

Now, for those of you contemplating a switch, have you made sure you are doing everything to make the most of the insulin you are currently using? Are you being very consistent day to day with the amount fed and the dosing regimen? Are you doing all the things your veterinarian told you to do? Are you feeding the prescribed food? Or are you sliding Fido some of potato chips you munch on when you are watching TV? (It’s like when your dentist asks if you floss every day…) Before you make the financial and time commitments of changing insulin and syringes for your pet, let’s make sure we stress consistent patterns! Consistent day-to-day routines matter for diabetic pets.

We at ADW try to keep you abreast of current developments in diabetes management. As always, we urge you to speak with your own veterinarian to decide what is best for your pet.

NOTE: Consult your Veterinarian first to make sure my recommendations fit your special health needs.

About the Author: Dr . Joi Sutton

Dr. Joi Sutton is a 1993 graduate from Oregon State University. She has practiced both in emergency medicine and general practice. Dr. Sutton has done extensive international volunteer work though Veterinary Ventures, a nonprofit organization that takes teams of veterinarians to undeveloped countries for humane medical care. She also runs a small animal practice in South Florida. Connect with Dr. Joi on LinkedIn


  1. Phyllis June 12, 2015 at 8:13 pm - Reply

    I buy my vetsulin through Alivet. Even though there is a hefty shipping charge, I buy five at a time and it more than makes up for it. Here in SoCal it is about $58 per vial locally and through Alivet it is about $35 + ONE shipping charge.


    • Larry Silkaitis June 28, 2015 at 4:25 pm - Reply

      The statement “Using U-100 syringes with a U-40 insulin could result in overdosing your pet.” is not true. If you draw a U40 insulin up to the 1 unit marking on a U100 syringe that is only 0.4 units of the U40 insulin. Thus, not an overdose. You can however overdose if you use U40 syringes for a U100 insulin. In that case drawing up a U100 insulin to the one unit marking on a U40 syringe draws up 2 1/2 units of the U100 insulin.

      • Dr Joi July 1, 2015 at 5:20 pm - Reply

        Larry, what I meant is that if using the inappropriate syringe one could make a math error and dose too high OR too low. The worse case scenario in an acute situation is to overdose. It’s just much better and far less confusing to use a u-40 syringe with a u-40 insulin. 🙂 Joi

  2. Dan December 5, 2014 at 11:50 am - Reply

    Does ADW carry Vetsulin? I don’t see it offered on the site. I’m looking to find it cheaper than what I’m having to pay through Valley Vet. Thanks!

  3. Dr Joi September 27, 2014 at 1:42 pm - Reply

    Lakyn, you will need to check with your vet clinic as to what they charge for Vetsulin. Some vet clinics mark up their meds very little while some mark up the cost of meds more. Veterinarians purchase medications and syringes and medical supplies from a variety of distributors. Even the cost of supplies can vary from distributors. You will need to check with your doctor regarding the exact cost you will pay at your clinc. Make sense?

  4. lakyn September 20, 2014 at 10:39 am - Reply

    how much does it cost

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