Insulin Syringes & Overweight Cats

By Dr . Joi Sutton|2016-12-29T15:26:52-05:00Updated: August 22nd, 2013|Pet Care, Pet Diabetes, Pet Newsletter|0 Comments

Dr. Joi answers more questions from our readers:

“Can I use these U-100 syringes with this U-40 insulin?”

I just got this question last week. Sometimes clients have access to left-over or free syringes that do not match the type of insulin their pet is receiving. I’ve been told there are conversion tables on the internet for using U-100 syringes (the type for most insulins on the market) for U-40 insulin (the concentration used for PZI and Vetsulin). Please don’t do it.

Twenty years ago when I started practicing they didn’t have the nifty 3/10 cc syringes, let alone the 3/10 cc syringes with half unit markings. I spent my first 8 years of practice as an ER vet. I lost count of the times I saw cats in a diabetic crisis (whether in diabetic ketoacidosis or a hypoglycemic event) and the client mentioned that just recently they had a new bottle of insulin diluted. Math errors do happen. Math errors can be devastating to a diabetic pet.

Veterinarians understand that treating a diabetic pet is expensive. Most families do not have pet insurance for their diabetic pet. (I suspect families with diabetics or other expensive chronic care conditions are more likely to invest in pet insurance for their next critter after shelling out the bucks for the current pet.) Nonetheless, unless you are a gifted mathematician, I sincerely advise you not to try to calculate the amount of U-40 insulin to give in a U-100 syringe or vice versa if you still have syringes left for U-40 insulin and your vet has changed your pet to U-100 insulin. I personally will never do the calculation for a client. That’s how much I oppose this idea. One little math error and a visit to the ER will cost many times more than the amount saved on syringes.

“My cat is overweight. Should I worry about diabetes?”

Yes! You are wise to associate obesity with a higher risk of type 2 diabetes in cats. If you are going into your veterinary office for an annual exam, discuss weight loss approaches for your kitty. Your veterinarian may even check your cat’s blood glucose level to check for a pre-diabetic state. It might be best to mention this to the receptionist so that the vet or tech can get the sample of blood prior to the exam… Cats may be more stressed after the examination which results in a stress hyperglycemia. Whether your goal is weight loss for your cat’s quality of life or to decrease the risk of diabetes, a canned food diet makes it easier for cat’s to lose weight. Obesity is one of the leading causes of insulin resistance in cats. Portioning your cat’s meals and feeding solely low carbohydrate, canned food (particularly those not containing rice and potato) and regular weekly to monthly weigh-ins can decrease the risk of your cat becoming diabetic. Speak with your veterinarian about a weight loss plan for your cat if your kitty is overweight.


NOTE: Consult your Veterinarian first to make sure my recommendations fit your pet’s 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

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