FYI – Switching Insulin
There is so much to learn when we are told our dogs are diabetic and require insulin injections twice per day for the rest of their lives. Twelve-hour schedules, insulin, syringes, injecting and handling insulin properly are all things that we quickly learn about. But what if the type of insulin your sweet pup is on isn’t the right one and you need to switch insulin?
Lucy started on Vetsulin (Caninsulin) after she was diagnosed with diabetes. Once I started running curves at home, I noticed that she was never consistent, and while she was always a bowl curve, blood glucose was never nice and steady. I was concerned that I would never get Lu to target range of 100 – 250 mg/dL (5.55 – 13.88 mmol/L) and that was really important to me because I knew that lower blood glucose levels meant organ preservation. You may or may not know this, high blood glucose levels damage blood vessels which leads to organ damage.
After speaking with my vet regarding my concerns we switched Lucy from Vetsulin to Novolin N. Different insulin, different syringes, different handling…all I could think of was, what are these numbers? Why did I have to reduce insulin by one unit when I switched from Vetsulin to Novolin N? Why did I have to purchase different syringes?
Today I am going to go over some basics so you understand the differences in these insulins you may be switching to.
What do these numbers mean: U40 vs. U100?
- U40 insulin – Vetsulin, Caninsulin, Prozinc. U40 insulin has 40 parts of insulin per 1 cc or mL.
- U100 insulin – NPH Insulin (Humulin N, Novolin N), Detemir (Levemir), Glargine (Lantus). U100 insulin has 100 parts of insulin per 1 cc or mL.
Why is it recommended to reduce insulin when switching from U40 insulin to NPH insulin?
- They are different concentrations. There are more parts of U100 insulin per cc (mL) than there are in U40 insulin.
- This also means that U100 insulin is 2.5 times stronger than U40 insulin.
- Due to this, it is recommended to reduce insulin by one unit when switching from Vetsulin/Caninsulin to NPH insulin.
What is the difference between U40 and U100 syringes?
They hold different volumes of insulin.
- A 0.3 cc (or mL) U40 syringe holds 12 units of U40 insulin.
- A 0.5 cc (or mL) U40 syringe holds 20 units of U40 insulin.
- A 1.0 cc (or mL) U40 syringe holds 40 units of U40 insulin.
- A 0.3 cc (or mL) U100 syringe holds 30 units of U100 insulin.
- A 0.5 cc (or mL) U100 syringe holds 50 units of U100 insulin.
- A 1.0 cc (or mL) U100 syringe holds 100 units of U100 insulin.
This is why it is necessary to use the correct syringes with insulin. U40 syringes should be used with U40 insulin. U100 syringes should be used with U100 insulin. If you use a U40 syringe with U100 insulin you will overdose your dog. If you use a U100 syringe with U40 insulin you will under dose your dog.
And don’t forget proper mixing instructions for each insulin.
- NPH insulin should be gently rolled.
- Prozinc should be gently rolled to mix.
- Vetsulin and Caninsulin should be shaken vigorously to mix properly.
- Lantus does not need to be mixed, do not roll.
- Levemir does not need to be mixed, do not roll.
Please always read product insert instructions, they are printed by the manufacturer, so they know what they are talking about!
Switching insulin may be necessary for your diabetic dog and I hope this blog has been helpful and you now understand what all these numbers mean!
If you have any questions, comments or suggestions, please start a conversation below.
Until next week stay comfy, cool and caffeinated!
Michelle Miller-Matlock
AAHA Certified Diabetes Educator
Administrator of Diabetic Dog Owners on Facebook
Founder/Administrator of DDO: Diabetic Dog Owners University
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