Can you use a human glucometer to do a blood glucose reading on a dog and is one test sufficient to make a diagnosis of diabetes?
Original Question: Dear Doctor Greenway, thank you for taking my call today on your radio station. I was asking about Leila a 13-year-old dog. You mentioned that someone could do a diabetes test for $20. I had just done a test on myself before calling you. I have all the equipment. I wonder if it would be safe for me to do it on the dog. I would need to know if it is okay to administer the needle in the arm of the dog instead of the ear. I would also need to know what number would mean the dog is diabetic and also when the best time is to administer the test (e.g. how many hours before or after eating). I am not a healthcare worker or vet myself. Even if Leila’s owner gives me permission to go ahead I will be shaking in my boots doing it. I am still shuddering from the time I had to give my older sister a needle about 15 years ago. I won't be seeing Leila’s owner before Monday I am only an acquaintance. I have helped her once in the past but now I have about $20 000 of work to be done on my house and I am a senior on a fixed income. I also want to thank you because I phoned in once before about a cat who had to be moved to different locations. You recommended a spray and it worked beautifully. This is a great work you are doing and I do appreciate it you very much. - Marie
The first thing to mention is that veterinarians can perform a ‘spot glucose’ reading which is inexpensive. They’ll can take a few drops of blood from a vein or the edge of the ear and check a blood glucose reading on a glucometer during an appointment. It is inexpensive, but you’ll also have to pay the appointment fee. They will also tell you like I will that a one-time blood glucose reading is not to be trusted. It fluctuates throughout the day. A more reliable spot glucose reading would be a ‘fasted’ blood sample done first thing in the morning. A dog’s normal glucose reading should be between 2-7 mmol/L. If the reading is between 7-10, it could just be high as a normal fluctuation. If it comes back over a level like 18, it certainly is more LIKELY, but not certain, that diabetes is present. Technically, you should not diagnose diabetes off of one single reading. There is a product in the blood called ‘fructosamine’ which is more reliable at confirming diabetes because it elevates once the glucose levels have been chronically elevated over a 3 week period, but the test is more expensive than a spot glucose reading.
If a spot glucose reading is markedly elevated, a veterinarian may consider making the diagnosis of diabetes in a case where there is limited ability to test. However, prescribing insulin then becomes a bit dangerous because if you’re wrong, you could cause harm. Insulin is a drug that needs to be finely managed because too much of it can cause hypoglycaemia and if it’s severe, it can be fatal. So most veterinarians will likely refuse to treat unless they are able to adequately diagnose.
You could try performing a blood glucose reading at home. You can buy the glucometer and strips from your local pharmacist. I would not suggest you collect the blood from the arm unless you have experience with this on canine patients. There are many clients that are taught how to collect blood from the ear margin and one of the Registered Veterinary Technicians at your local clinic could show you this. I have taught many owners to do this and then they could perform ‘blood glucose curves’ at home. It has advantages as well. First, the obvious reason is that you won’t have to pay for it. By doing it at home with your own blood glucometer, you won’t have to pay the expensive hospitalization fees and technical costs of collecting samples all day long. Second, your friend’s dog is much less stressed at home rather than at the veterinary office and this could yield more reliable result if you are performing it correctly. I believe that blood glucose curves are more accurate when they are performed in the patient’s natural environment.
I always have my staff show clients how to perform a blood glucose curve so that they can do it at home. Some veterinarians may not want to take the time or use up their employees time to teach you how to do this. There is another problem as well. Once you collect the glucose reading, you will have to call your veterinarian and have him or her assess it. I always do this for free, but other veterinarians may not. Please keep in mind that it takes a veterinarian’s time and expertise to interpret a blood glucose curve. Charging a fee for this is not unreasonable. If your veterinarian does not want to demonstrate how to collect blood for a blood glucose curve, I suggest you search for one that will. At the current time, we do not have a video of this on our website but we will at our next opportunity for filming.
I would recommend that you forge a strong trusting relationship with your veterinarian and also find one who is willing to put in extra time without compensation based on this scenario. They could then assess the blood glucose readings you collect, give you guidance and may be comfortable enough to start treatment without extensive diagnostics. If they do, they’re very nice and understand that finances are a barrier that can be worked with. However, I would tell you that you should not be disappointed in a veterinarian who doesn’t offer this. Working through a scenario like this can legitimately put their license at risk and that has to be respected.
I hope this helps and good luck.
Dr. Clayton Greenway
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