Diabetes tests and testing equipment in Cats


Diabetes Tests and Testing Equipment in Cats


Using human glucose meters for testing pets

Question: Thanks for the newsletter, and congratulations to the new graduate!! Can I use a human glucose monitor for my dogs, and if so, what is the acceptable glucose reading? For a 30-35 lb. male Frenchie, 6 years old; and a 40+ lb. female blue heeler who is 2 and 1/2 years old? Thanks so much, Jean

Answer: Jean-

The human glucose meters are the glucometers that I was referring to. I should have made that more clear in the newsletter.

The normal range for blood glucose for dogs is around 60 to 110 mg/dl or 3.9 to 6.1 mmol/L.

The normal range for blood glucose for cats is around 70 to 140 mg/dl or 5.9 to 10 mmol/L. Some cats can get their blood sugar as high as 250 mg/dl if they are stressed, though. This makes it a little harder to interpret high glucose readings in a cat.

If there is a reason for routine screening for diabetes, like a known family tendency in one of the dog's lines, using urine glucose strips is easier than trying to draw blood and use a glucometer. If there is glucose in the urine, then checking the blood glucose would be a good idea and your vet can help you determine the best way to correct the problem.

Mike Richards, DVM 6/10/2000

Diabetes - treatment with home testing

I have a 15 year old cat Maya, who was diagnosed with diabetes in April. I understand that you have clients that home-test (as we do) and I'm wondering how you structure your treatment plan while regulating and then managing diabetic animals, when the owners can test bg's at home. What is your general approach to diabetes treatment, assuming willing clients? Can hypertension be a factor, and do you treat proactively? In Maya's case, she seems sensitive to insulin, but her response to the same dose will vary greatly from day to day, and I don't know why. I don't think it's her diet, or how much she eats, because that's pretty consistent. She does have chronic gingivitis which I've been keeping at bay with Clavamox, until the diabetes could be controlled. (However, it has recently flared up, and her bg's have also been very low all of a sudden (at least in part because she eats less when her mouth hurts)) Do you think that her underlying gingivitus might make her response so variable? Has it been your experience that having her teeth removed would resolve this condition? How "regular" are cats' bg's usually, assuming no other illness? I would think that it would take home testers to know this, since most vets seem to do only one-day bg curves. Thanks for your writing on risk assessment in the Digest this week. It was very thought provoking, and worrying. (and I think you are under-charging for this great service that you provide on line). Thanks for any thoughts you might have.

Gratefully, L and Maya

A: When we have owners who can easily test blood glucose at home, we try to get them to do blood glucose curves in which the blood levels are checked every four hours for 4 tests, to give us an idea of how well the insulin is working over the course of the day. We usually try to get this done every two weeks or so until the owner is good at recognizing the clinical signs of under or overdosing with insulin (attitude, appetite, and water consumption changes that signal a problem). Then we back off and go for longer intervals, depending on the client. If I ever have a cat that is really willing to let blood be drawn, I'd really like to see if it was possible to adjust insulin for activity, illnesses, stress, concurrent illness and all those other things that can affect insulin levels. I know we could do a better job of insulin dosing in most patients -- but blood is just very hard to get from a cat and doing it too often makes the process even harder.

I have seen or heard (my memory is failing on which one) a recommendation to use anti-hypertensive agents in diabetic patients, on the assumption that most have, or will have, hypertension due to the effect of diabetes. I have not routinely dispensed these medications but have tried them in a couple of patients. Since we do not have the equipment to monitor blood pressure in our practice, we can not prove or disprove the need or the actual effect on blood pressure, though.

I do think that any underlying illness can affect blood sugar and I also think that more antibiotics cause changes in the blood sugar levels -- or in the levels the tests detect, than we are aware of. I checked to see if this had been reported for Clavamox (Rx) and did not find any indication that it did. The best you can do in these circumstances is to pay really close attention to Maya's daily routine and try to make adjustments to the insulin dosage as need be -- but this should be done after consulting with your vet, who knows you and Maya personally and can assess how much change to make in dosages or even if this is a good idea at all.

Hope this helps some.

Mike Richards, DVM 9/8/99

Last edited 01/30/05


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...