Running a Blood Glucose Curve

By Dr . Joi Sutton|2016-06-13T16:29:14-04:00Updated: November 21st, 2013|Pet Care, Pet Diabetes, Pet Newsletter|4 Comments
  • Featured Image - Dog Sleeping

Glucose levels do vary from day to day, so when we run a blood glucose curve we want as much as possible for the day to reflect the pet’s “typical” day. We are evaluating if we are giving enough, or maybe too much insulin. We are evaluating how long the insulin lasts in the pet, and how long until it takes effect. Humans have such variability from day to day on their meals and exercise that they check their glucose levels multiple times daily. Pet owners of diabetic pets rarely want that level of elbow grease, so we tend to use periodic glucose curves to evaluate the dose. Of course, knowing how the pet feels is the biggest clue to good glucose control. Be in tune with your pet. If there is never enough water in the bowl, your pet likely is not controlled!

I strongly prefer home testing of diabetic pets. I think they tend to be more reflective of the true glucose levels when the pet is in the everyday environment. Plus, it’s a heck of a lot cheaper for clients to test their babies at home than to tote them to the clinic for a day of glucose tests. If a client does a curve at home I ask them to check the glucose level at the time of the insulin and meal. If a pet is going to the vet for the curve, simply feed and give insulin as you normally would then take your pet to the clinic. A pet is more likely to eat normally at home than in a clinic setting.

I recently had a client who would feed his pet then wait an hour to give the insulin. I’m not sure where he got this notion. I prefer both diabetic dogs and diabetic cats to be given a meal at the same time of the insulin injection. Once you see your pet is starting to eat, give the injection – hopefully your pet won’t even notice the poke because it is busy eating!

Dogs tend to empty the food from their stomachs faster than cats do, so it doesn’t matter as much for cats to get the insulin at the same time as the meal as it does for dogs. When a dog eats, the blood glucose may rise faster with the rapid stomach emptying time relative to a cat. This is why I don’t mind diabetic cats nibbling low carb canned food any time of the day but prefer dogs be fed twice daily at the time if insulin and AVOIDING mid-day snacks. If the dog IS given a snack, it should be low in calories or else the blood glucose will spike.

Let’s go back to most vets being okay with diabetic cats nibbling all day–on low carb canned food. This is not a case of discrimination against dogs! In addition to their relatively slow stomach emptying time, we take into account the nature of the beast. Most cats prefer to graze than meal-feed. This is not all cats, but a whole lot of them. If your cat is one who cleans up the food bowl twice daily, that is fine. Overall, it’s hard to train cats. Hence, in the yellow pages you may find a long list of dog trainers but you probably won’t find a cat trainer in your home town.

I prefer owners doing glucose curves at home. Some folks don’t have the gumption or agility to test their sweetie at home. In these instances we may forego the first glucose check (the one at the time if insulin and meal) and simply check it once the pet is in the clinic for the curve. It is best to let a pet eat normally at home than to feed the pet in the clinic. Some pets are just too nervous to eat in the clinic. We want the glucose curve to be as typical as possible on the day tested.

Some owners change the time of insulin injections a few days before a curve to accommodate clinic hours if the curve is to be run in the clinic. If you must this, change the dose a WEEK before the curve. We try not to run curves any sooner than 5 to 7 days after a change in insulin dosing.

If your pet has been ill that same week, hold off on the glucose curve until it has been back to normal health for a week or so. If your pet is still ill, get that critter into your veterinarian for diagnostics and an exam. Your vet may do spot checks while a pet is sick, but we rely on curves to evaluate dosing.

If you are to have a glucose curve at the clinic and your pet doesn’t eat breakfast that day, it’s not be worth running the curve that day. You will need to postpone it until things are as they usually are on a typical day.

Now, if your pet needs a nail trim or bath or some kind of test while at the clinic for a glucose curve, do it at the END of the day, after the last sample has been taken. Or, do it on a different day. Stress (even from a nail trim) could cause stress hyperglycemia and mess up the curve. Again, we use curves to evaluate insulin dosing, so do your best to make it a “typical” day.

I hope today’s discussion has helped you understand better how veterinarians utilize glucose curves and help you get the most of your efforts.

As always, I enjoy interaction with our readers. If you have any questions, feel free to contact me at [email protected].

NOTE: Consult your veterinarian first to make sure my recommendations fit your pets 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. Rita S October 20, 2020 at 5:59 pm - Reply

    I want to inquire on how to manage our newly diagnosed diabetic maltipoo baby. Her serum fructose amine yesterday was 500 we brought her to the bed this morning and she was given insulin three units twice a day and we were sent home. She had been nauseated and week and we tried to get her blood sugar poked her five times with a lancet device for humans but we can’t get any blood enough for the test. We finally just poked her with a Needle to get blood and we succeed and obtain latest blood sugar of 311. She is nauseated and vomiting so I tried to pushed about 60 ML of rice bran liquid into her mouth. That was when I check her blood sugar to be above 300. I want to be able to monitor her blood sugar hourly until I stabilize her. She won’t have her glucose curve until two weeks from now I am a nurse and believe that this is manageable at home. I totally agree with you when I watch the video that the key to properly managing it is to be able to know the exact blood sugar just like how you would manage a diabetic human. It’s basic on a insulin administration I am an adult and pediatric nurse in until we could stabilize her blood sugar I wouldn’t feel safe just giving insulin as prescribed by the bed. She is prescribed for three units twice a day but I think with a blood sugar going up as high as 500 I am not sure whether the three units is enough to manage her per kilogram body weight. It could be minimum but I still feel safe to know the blood sugar so I would know she isn’t hyper or hypo glycemic. Can you share your insulin sliding scale so I can apply it for my dog. She is 14lbs. She have lost 2 pounds in the last three days she peas a lot and throws up.

    • Dr . Joi Sutton October 26, 2020 at 7:15 am - Reply

      Rita, I responded to the email you also sent me before I saw this. Joi

  2. claudine January 8, 2018 at 12:21 am - Reply

    In your article about glucose curve, I see no mention of fasting. Don’t animals need to have fasted-like humans- for the base pre-insulin reading to be meaningful? (I am so much hoping that you will say that it is not so crucial as i am losing my hair over the conudrum: how to make one cat fast in a multi-cat household accustomed to round the clock free feeding, in a home without a spare room, without everybody, including me, going crazy!). If fasting is absolutely necessary, how long?

    Also, could you please explain how you go from there in order to adjust the insulin dose? Hit and miss, special value tables?

    Can I do the adjustment myself? My means are very limited and I prefer to keep as much money as possible to go to high quality food.

    I having difficulty getting the capillary each time with the lancet made for humans that i am using. Do you have a more precise one to recommend?

    Thank you so much,

    • Dr . Joi Sutton January 13, 2018 at 11:05 pm - Reply

      Claudine, don’t pull your hair out!

      The first blood glucose of a curve is a fasted sample. We frown upon mid meal snacks for diabetic pets. We get better glucose control when food and insulin are given twice daily, equal meals, 12 hours apart. So you see the first check of a 12 hour curve is fasted.

      When we run a curve we check the glucose every 2 hours from one injection til the next, 12 hours later. If the blood glucose drops below 150 we check hourly until it starts to rise. A curve tells us how long a type of insulin will last in a particular pet. A curve also tells us if we should increase, decrease or leave the insulin dose alone. We want the glucose to bottom out somewhere around 100 mg/dL.

      Checking the glucose at home can help folks of limited means, but nothing beats a veterinarian who has examined your pet. Consider yourself part of a team with your vet!

      🙂 Joi

Leave A Comment

Go to Top