Insulin Use for Dogs and Cats

April 28, 2018

Gary Edelson, DVM, discusses the proper storage and handling of insulin, the types of syringes available, locations to inject, and administration technique. Dr. Edelson also demonstrates how to draw up insulin into a syringe.

Gary Edelson, DVM: Storage of insulin is very important. It needs to be refrigerated, and in the refrigerator, there are different sections of the refrigerator that are evenly cooled. So, it's really important that we don't put the insulin in the door of the refrigerator. As the door keeps opening and closing, it can shift its temperatures up and down. Keep it protected from light, so on the second shelf or the bottom shelf. And keep it in its box and toward the back of the refrigerator to keep an even cool temperature throughout.

Insulin handling is very, very important, as some insulins, like ProZinc, are very fragile and they need to be gently rolled. Whereas Vetsulin needs to be shaken vigorously in order to get a uniform cloudy solution.

So, there are 2 different types of syringes when we're talking about handling insulin. One is the U100 syringe, which is commonly found in the human market, and then there's a U40 syringe, which is commonly found in the veterinary market with insulin products like Vetsulin and ProZinc. The insulin syringes are labeled as a U40 or a U100 based on the concentration of insulin molecules within each milliliter of solution. So, a U40 syringe is actually 2 times less potent than a U100 syringe.

Administration of insulin is really important, and we want to make sure that your pet is getting the correct amount of insulin. So, when we do administer insulin, it is given underneath the skin subcutaneously. It is really, really important to find a location that is comfortable for yourself as well as your pet when administering insulin. More common sites of administration are going to be between the pet's shoulder blades, on the side of its legs, or on the sides of its rear legs as well.

With insulin syringes, there are 2 types. One is called the U40, which is commonly found in the veterinary market with Vetsulin and ProZinc compared to the human market, which has U100 syringes. And these U100 syringes are actually 2.5 times more potent than the U40 syringes, so it's really important that we don't overdose or grab the wrong syringe, so our dog or cat is getting the proper amount of insulin. With any syringe, there are 3 main features. One is the barrel, the second one is the plunger, and the third is our needle. When we draw up insulin, the plunger has a top line and a black line on the syringe inside the barrel. The top line is what we judge off of, and we go on the graduation lines equivalent to 1 unit, 2 units, 3 units, 4 units, up to 5 units. So, it's really important that we deliver the correct amount of insulin.

When you get your insulin out of the fridge, you want to first have your needle ready. In this case, we're using ProZinc, so it's a U40 syringe. You want to remove the plastic cap, and you also want to prime the plunger by pulling it back and pushing it all the way forth gently. You're going to grab your insulin, in this case ProZinc; you want to gently roll it between your fingers and then invert it to get ready for the syringe. You're going to uncap the syringe, place the needle into the vial, and we're going to be giving 5 units of insulin. So, the graduation marks on the syringe on the barrel indicate 1 at each marking. We want to go past the 1, the 2, the 3, the 4, and the 5. We're going to go to 6, tap the syringe to get any air out, and then go back to 5 units. We're going to gently place the bottle down, carefully cap the syringe, and then grab our pet for the insulin.