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

NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs.

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 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.
Dr . Joi Sutton