I sometimes get emails questioning the accuracy of home pet glucose meters. Some folks get upset if their meter is 20 points off from what their vet’s lab work reveals. I think some people have unrealistic expectations about how accurate a meter can be. I can tell you first-hand that pet glucose meters are actually quite reliable, particularly the meters that are calibrated for pets.
If veterinarians say home glucose testing with handheld glucose meters isn’t as accurate as fancier blood analyzers they may be correct. But, I think they may forget that when glucose testing is run at home we remove the chance of stress hyperglycemia. Stress from being anxious in the vet clinic, commonly known as “white coat syndrome”, can significantly elevate a pet’s blood glucose levels. I personally have seen a couple of non-diabetic cats and small dogs have blood glucose levels up in the low 200’s just from anxiety in a clinic over the years. Even though the diagnostic lab equipment at your vet clinic is likely a bit more accurate than a handheld glucose meter, by taking your pet to the clinic you then introduce error from stress hyperglycemia in most pets. Unless your pet is cool as a cucumber in a vet clinic, the risk of stress hyperglycemia is high. Additionally, having a home glucose meter yields information at that moment in time that can affect our actions even in the middle of the night rather than waiting until you can get your pet to the vet. If your pet is acting goofy, you could check to see if the blood glucose is low. I can’t imagine having a diabetic pet without owning a home glucose meter.
Do I expect the blood glucose from a handheld blood glucose meter to be EXACTLY the same as my in house Vetscan chemistry analyzer or the reference lab, Antech Diagnostics, that I use at my own vet clinic? No. I expect there to be a bit of variability, but in general the results are pretty close. I frequently do “quality control” on my in-house chemistry analyzer compared to the lab work I send out to Antech. For example, if I have a very sick pet present to my clinic in the afternoon and know I wouldn’t get Antech chemistry results back until about 10PM when my clinic is closed, I may start with an in house chemistry which has less information than a chemistry from Antech. Many outside profiles also include CBCs for just a bit more than a CBC alone, so I don’t mind duplicating some information just so I can run quality control on my equipment. I may run some lab work in house to get important information immediately such as kidney and liver values and electrolytes, to give me a direction for initial treatment, and then also send blood out to Antech.
Not only does each chemistry analyzer have a slightly different normal range for each lab value, the results may vary slightly. I want to know that they are close but I don’t necessarily expect the exact same number. If I had to reflect on the range, I’d say there could be a difference for blood glucose of 20 to 40 points between the outside lab and my in house chemistry analyzer and the glucose monitor that I use in my clinic when I do this “quality control”. Remember, each machine has a slightly different range for “normal”.
Just a few things to know about blood glucose meters, whether pet or human meters: Any glucose meter will be more accurate around a relatively normal blood glucose level. It’s harder to get an accurate reading if the blood glucose is very low or if the blood glucose is very high. Know that in general, human meters are thought to underestimate the blood glucose levels in dogs and cats. I was told this fact years ago by a sales rep and it has resonated true in my communications with clients in years since.
This is not to say I have never used a human meter on a pet. Back in the 90s we veterinarians only had human blood glucose meters, so that is what we used. Now that we have blood glucose meters calibrated for dogs and cats, I strongly advise sticking with a pet glucose meter.
Cats and dogs and humans all have a different amount of blood glucose within the red blood cell versus the plasma. This is a species difference. I feel more comfortable with a meter that is calibrated for the particular species. Sometimes pet owners balk about the higher price of pet glucose meters/strips compared to human meters/strips. Here’s my take on this – When you think of what impact these numbers have on our choices and the cost that an uncontrolled diabetic can run, sometimes a hundred or more dollars for a nasty urinary tract infection to thousands of dollars for diabetic ketoacidosis, the cost of the test strips isn’t so unappealing.
In general, pet glucose meters are much better than they used to be and require less blood to get a reading, even on our smallest patients. Back in the old days, folks had to take their pets to the vet clinic for blood glucose curves. Not only was there then often stress hyperglycemia, and the aforementioned white coat syndrome, it was a heck of a lot more expensive. A re-check exam and a blood glucose curve at vet clinic could easily cost you a hundred bucks. A home glucose curve with any blood glucose meter designed for pets wouldn’t be anywhere near that cost.
If you haven’t been checking your diabetic pet’s blood glucose at home, now may be the time to start!
Have a question or comment? Post below or email me at firstname.lastname@example.org. I always enjoy hearing from my readers!
NOTE: Consult your veterinarian first to make sure my recommendations fit your pets special health needs.