The blood glucose level in non-diabetic dogs usually runs between about 70mg/dL and 140 mg/dl. In those fortunate dogs, pancreatic beta cells are continuously monitoring blood sugar levels and releasing insulin into the system as required. But dogs that have blood glucose levels persistently greater than 200mg/dL have diabetes.

With the medicines of today, there is no way you can duplicate the normal situation with injected insulin. The best you can hope for is to keep your pet's blood sugar level between 100mg/dL and 150mg/dL. Occasional owners can attain that, but most will find that their dogs peak (spike) considerably higher.

Larger or more frequent doses of insulin will drive down these glucose spikes. But that can be dangerous. You do not want the valleys (nadirs) in your dogs daily glucose levels to be too low (lower than 80mg/dL) because at slightly less than that, the dog will become hypoglycemic. With AM and PM injections, their should be two nadirs. The morning one is usually the lowest.

The safest Low Nadir Point for a dog in insulin therapy is about 90 - 100. That is because, after the insulin injection, glucose follow a skateboard track downward and you will never know from your last glucometer reading how close you are to the bottom. So fudge on the side of caution.

If your pet is persistently running over 200 - 250 mg/dL you should at least try to modify its treatment procedure to gain better control and regulation.

To obtain tighter regulation, will probably require quite a bit of home blood glucose testing and effort on your part – at least at first. No matter how hard you try, it is not always possible. But please try not to get exasperated or make rash decisions on your own. You get to choose your veterinarian. But the veterinarian, not you, is the one who is trained to make these decisions.

Interpreting the glucose curves

Your dog needs to stabilize 7-10 days on any given dose to get an accurate curve. You must make the graph during a period of home tranquility and stability or it will be of little value. Some veterinarians suggest they do it at their animal hospital. That's OK if, for some reason, you can not do it at home. But that will be more stress on your pet and the insulin/glucose curve you get there will not be identical or as accurate as the one you make at home.

When you prepare the graph at home, you know the pet ate and what it ate. You know its insulin needs were not lower do to an empty stomach, or higher due to stress. You can add significant events of the day to the graph to try to help interpret the curve e.g. injection points, meal points, exercise points, disruptions.

Some questions to consider

How long did the dose of insulin have an effect? No effect might mean that your injection technique was inappropriate, the medication was old (expired) or improperly stored, or the dose was insufficient.

Too low a nadir might mean that the dose was too large or your feeding plan needs alteration. Keep track of when they occur - you don't want potentially dangerous nadirs occurring during times of the day when you are preoccupied or aren't around.

How long did the injection keep my pet's blood glucose in an acceptable range? Was there evidence of a post-injection spike (Somogyi effect). Was the dose too low or could a different mix of insulins have produced a more lasting control?

Too long a lag-time until the dip might mean that the insulin was poorly absorbed or destroyed by the pet's immune system.

Find out if and when urine overspills of glucose are occurring (about 180-200 mg/dl) by checking your pets urine with a glucose dipstick 30 minutes after the peak blood glucose graph point.

The proper dose of insulin should keep your pet's blood glucose levels in an acceptable range for about 12 hours (10-14hrs). Low point (nadir) should occur about 8 hours after the injection.

Your dog's graph is affected by what it eats. most likely, feeding your pet two equal size meals, each just after its insulin injections, will give it its best blood glucose control. Food and insulin work in tandem, affecting each other and blood glucose in your pet. But you can make whatever healthy variations that might be required to obtain the most stable and acceptable blood glucose levels that you can.


Back To Main Article