Two weeks ago I got a new patient. He came to my clinic for a second opinion, as well as a quote for a dental cleaning and extractions of some abscessed teeth. And, by the way, he is an 18-year old uncontrolled diabetic cat. I thought this patient would be a good example for our readers to understand why vets do what we do with diabetes.

The owner had no clue that I take an interest in diabetes, nor that I am the staff veterinarian for ADW Diabetes. She had just heard in our relatively small town that I’m affordably priced and good at dental work. He had some ulcers on his tongue and mouth with enough jaw swelling such that his lower left canine tooth had fallen out. We needed to address these issues and get him eating normally before we could truly evaluate his glucose regulation. He wasn’t eating well due to the oral pain, which makes it hard to manage diabetes. Our initial plan was to address the infection in his mouth and pull the bad teeth so that he wasn’t drooling and was eating well. Then we’d run a glucose curve.

Now, this putty-tat is fine cat and ever so charming to his family, but had a history of having a short fuse in the vet clinic environment. This “cattitude” is probably why he hadn’t had a glucose curve at the prior vet clinic. And this is probably also why the prior vet hadn’t asked the owner to run glucose curves at home. After all, what vet wants to be blamed if a crabby cat bit or scratched the pet owner!

I asked that day if the owner was willing to try home glucose testing. She wasn’t that day, but at least I planted the seed in her mind. I often convince owners to do home glucose testing – even if their first instinct is “no”. I just show them a time or 2 in an exam room how easy it is and soon enough they believe me. I started that day by running a chemistry and CBC and urinalysis. I also started an in-house urine culture and took a few X-rays of his jaw and gave him an injection of antibiotic that lasts for 2 weeks. His lab work came back fine except his blood glucose was at 52 mg/dl. That sample was about 5 hours after his morning meal and insulin. Uh oh. As you know, a blood glucose of 52 is too low.

Blood Glucose CurveClearly the insulin dose was too high if the blood glucose was down at 52. We don’t know if that was the low point or if it actually had gotten even lower than 52, as it was just a moment in the day, not part of a curve. And we don’t know what it would be if he had been eating normally, but that day it was too low. He was on a pretty high dose of insulin for a cat at 5 units twice daily. I still knew nothing as to how his glucose curve would be, but I knew we needed to drop the dose. This is an example of when a spot check (which was actually part of a full chemistry panel) told me that I needed to alter the insulin dose.

When we run a blood glucose curve we strive to have a typical day for the pet. The feeding is the regular routine and regular amount. The exercise level that day is the typical level for the pet. The day is as usual as it can be (not considering that the lancing device comes out now and then so you can get a droplet of blood). We are looking to see how long the insulin lasts in that pet. And we are seeing how low the blood glucose level goes. We check the glucose every 2 hours from one injection of insulin until the next. And if the glucose drops below 150 mg/dl we check hourly until it rises so we don’t miss where it “bottoms out”.

Why do we care how low the glucose goes?

We care because that tells us if we can increase the insulin dose or if we need to decrease the insulin dose. I consider the ideal curve to look something like this: most of the glucose numbers are below 300 (so that the pet isn’t excessively thirsty and isn’t urinating voluminously because we are at or below the kidney threshold of glucose), and the lowest number is somewhere around 100. If the numbers are in the 400s and 500s and bottoms out in the 200s your vet will likely increase the insulin dose slightly. If it bottoms out at 60 your vet will likely decrease the insulin dose slightly. Every situation is a bit different. We adjust accordingly. If we can’t achieve success then occasionally we try a different insulin.

My newest diabetic patient is recovering from his oral surgery. His human brought him back to the clinic for a lesson with an at-home glucose meter. She felt she needed to come back once more to check his glucose in front of me to make sure she had the technique down pat. She did just fine. She will be running his first glucose curve in a few days. I’m very proud of her.


NOTE: Consult your veterinarian to confirm that my recommendations are applicable for the health needs of your pet.

Dr . Joi Sutton

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 and is the President and Founder of 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.
Dr . Joi Sutton