So, having assessed our glucometers and found that they are, are, are good and that they're giving us consistent reliable results, how do you go about using those in the stabilization and monitoring of diabetes? Well, as we've already suggested earlier on, you can use glucometers to help you make a diagnosis, and, in this respect, diagnosis of diabetes is fairly easy. Stabilizing animals with diabetes is more tricky, and is more, takes longer.
Before we start, we need to decide what is a stable diabetic. Is it a fructosamine concentration, a hemoglobin concentration? An animal that doesn't have ketones, an animal that's not losing weight.
An animal that's not bothering you, and you're not bothering it except to sell it insulin and needles. Is it a blood glucose curve like whatever you fancy? It is really important that we establish in our own minds what a stable diabetic dog is.
And then make sure that our owners and our colleagues and our nurses are all agree that this is what we're aiming with this particular dog. Now I'm not going to say that there is one of these that is absolutely the right answer here, but the wrong answer is not to have an answer, because that way leads to inconsistent messaging with owners, with one vet trying one thing, one vet trying to go another way, and it ends up with confusion all round. For me, at any rate, the main thing is that a stable diabetic is, is a diabetic that is being treated for diabetes.
And has no significant clinical signs of that diabetes. It isn't a blood glucose concentration, it isn't a fructosamine, and it isn't an HbA1c. Or glycoslate hemoglobin, it is a clinical decision.
And to achieve that. stable state. We need to ask some questions about the owner's abilities, about the animal's concurrent conditions, about the animal's adaptability.
Some dogs, you know, it's no problem to inject. Some cats very difficult to inject, about finances, about, whether we want to get it, beautifully controlled very quickly or we're prepared to take longer at it. Where are we going to do it?
And how are we going to monitor? If one vet does one sort of monitoring and another vet does another sort of monitoring, you end up with confusion. And then how are we going to adjust the dose based on that monitoring?
These all need to be considered before we start getting involved and then having been considered, we need to start writing this down so that subsequent vets, subsequent nurses getting involved, know what the plan is for this animal. Before we get too much into the actual stabilization, it's important to say that entire female diabetic dogs should be neutered as soon as humanly possible. It's your one chance to cure diabetes.
It is going to be almost impossible to stabilize an entire female diabetic dog. Any consistent length of time, and you really don't need them to be stable to go through surgery, just that they're not in diabetic ketoacidosis. As long as they're eating, as long as they're drinking, you can neuter them, and that is the best way about going about trying to save this dog from a lifetime of injections.
That aside, my basic stabilization for dogs is to use urine glucosis. We would give plenty insulin twice daily. We'd feed at 0 and 12 hours, wait 5 to 7 days, and then adjust the dose based on average morning urine tests.
And will carry on until that dog is clinically stable, or has, you know, is, is now entering their realms of insulin resistance and you're giving more than 2 units per kilogram per dose. And at that point, I would then check with a blood glucose curve or a continuous glucose monitoring system that I had in fact got stability. But this is on the basis of average morning urine tests.
And note that it only works if you give the insulin twice a day. If you give the insulin once a day, you need to be doing afternoon urine tests because the dog will be unstable at night. This urine testing is sometimes forgotten by a lot of people.
It, it, it's useful, it's very much cheaper than any other form of testing. It's important to check the date on the urine dipstick, and it works quite, quite well. The disadvantage is that if there, there is no glucose on average in the urine, you don't know if that dog is well stable, or it is overtreated.
Whereas if there is glucose in the urine, you don't really know how unstable it is. So these are really just approximations, and, and reflect the fact that if it is a cheap and quick monitoring technique, but it is not that accurate over, over 24 hours, and other additional measures need may need to be brought in to help you decide if this animal is stable or not, which we'll come on to. The more advanced method of stabilization is to do start again, lenty insulin in dogs or prozinc in in cats twice daily in the both cases, and then do some sort of glucose curve, and that might be a blood glucose curve.
Or an interstitial glucose curve with one of these continuous glucose monitoring systems. I like to refer to these interstitial glucoses as skin glucosis. So I'm talking about a blood glucose curve or a skin glucose curve.
And that, that can be a much quicker way of getting animals stable. It's safer and it's more reliable, and you can usually increase the insulin, a lot quicker. What I don't look at very much are single blood glucose measurements when I'm stabilizing diabetic dogs, because if the blood glucose is normal, you don't know what's happening the rest of the time.
The dog may be overtreated, it may be undertreated. If the glucose is high, it may simply be that the insulin has lasted too short a time and is now no longer working, or the insulin has never worked at all. The only thing that you can say from a single blood glucose point is that if at any point the blood glucose is less than the reference value, say that's 3.5, so anything less than 3.5.
That you have overtreated this dog and that you need to back off. So low glucose is I look at, but higher normal ones I do not. But when we look at a a blood glucose curve, then we're getting far more information because we are getting information that can be interpreted in terms of the pattern more than the single value.
So what I look at with the blood glucose curve is not so much the absolute values as the pattern. And there are a lot of the issues about whether the, the, monitor is, is, is reading 8.4 here or 5.6 or 10.2 become less because that error will be on average over time less, so that the pattern will be the same.
And what you find is these blood glucose curves done with glucometers, while they may not give you the same absolute values, they do give you the same pattern as if you use a reference method. It's important to remember that stress will affect the, blood glucose curve, so the decision whether to do the curve in hospital or at home will be as much a psychological assessment of the dog situation as it is about any other practicalities. Diabetic dogs do not want to have, do not like having normal glucose, and that's because the insulin is not there all the time.
And because of that, most diabetic dogs are happier if their blood glucose is a little above normal, and indeed in some instances above the renal threshold. It is important not to try to overtreat these dogs because you risk hypoglycemia. This is a 12 hour glucose curve, done in a dog with, as you see, the normal range shown there and the renal limit shown there.
And you can see here that there are two curves on the grass, a dashed line and a solid line. And the rhetorical question is, what would you change the insulin dose of the, of the solid line? The dash line, you probably wouldn't, or at least I hope you wouldn't.
But the solid line, I think it's reasonable. Could you, would you change the dose or not? What about this, this line?
Would you change the dash light? Clearly you would in the solid line, but would you change it in the dash line? Finally, here, what about these two curves?
If you put these curves in front of people who spend their lives doing diabetes, they will disagree. And if they disagree, vets in primary care practice may also struggle to be sure about their interpretation. One of the problems of interpreting glucose curves is that it is a subjective art, and it's not always, the, the, easy, thing to interpret.
It's also worthwhile saying there is enormous day to day variation. I just showed you 6 lines from diabetic dogs. They were in fact the same dog.
On 3 visits to a hospital, 2 curves each time, 1 week apart between each of those visits. No change in insulin dose, timing, exercise, or food. Blood glucose curves cannot be seen in isolation.
They must be interpreted with other evidence. If the animal is unstable, are there clinical signs? If the animal is stable, how good is is the information about that stability, and if the animal is stable, I wouldn't worry what the blood glucose curve is showing.
The reason why I don't worry if about it is that I know that I can take a, an, a good, well stabilized diabetic and stress it. Sufficiently to make its blood glucose curve look horrible that day just by sticking a needle in, just by going on and sampling, never mind putting it into the hospital and having a little puppy barking all day at it. These can have very significant effects on, on blood glucoses and therefore it's important that any glucose that you look at, you should look at in the round in the average, as much as the urine samples are done in the average and in the round, you need to look at the whole picture and over more than one day of observation before you start making too many decisions.
Doing things at home can help things, but owners do need training. They need more advice on how to look at these curves, and the fact is that these are therefore only suitable for some owners. If the owners are upsetting the dogs by doing this, then the stress will still be an issue.
And as I said, again, particularly, you need to look at averages, in this situation because owners may well influence the results that they're getting, if they just do it once a day. So when I look at a glucose curve, whether that's a skin glucose or a blood glucose curve, I am really looking for three things. I am looking for the time that the glucose starts to first go down.
That's the onset of action. I'm looking for the low point. And that's the Nadia.
And I'm looking for how long before the insulin breaks through its pre pre pre-treatment value or breaks through the renal threshold, and that's the duration of action. And using those three things, I can then determine two things. If the nadir is too high, then I can change the dose.
If the onset of action is too slow, then I can change the insulin type. If the free duration of the action of the incident is too short, then I can change the frequency. And those are the 3 bits of information that guide us in terms of our assessment of blood glucose curves.
So, putting this into into practice, a, a, a, a, this is a blood glucose curve. We can see here that the onset of action is almost immediate. This has been very fast.
The glucose has come down. It has not gone into the normal range, below 10. And it's then broke broken out.
The dose, therefore, is wrong because we've not got, got there. I suspect the duration of action may be too short. Increasing the dose does not increase the duration of action that much.
And I suspect the onset of action has been too too quick. So there may be an issue about timing of feeding here and thinking about that or about insulin type. So if this was a dog, for example, on 0.4 units of lenty insulin once a day, I would increase that to 0.6 units, and I might discuss with the owner about switching to twice daily insulin.
This is probably the more, more common situation I see, which is that, the insulin again has shown an immediate onset of activity. The, the, the glucose has got down to, somewhere less than 10 millimoles. But then within 12 hours, we're back through the renal threshold and we are heading on up to pre-treatment values.
This would suggest to me that their insulin is not lasting long enough, if we want it to last that so we might want to change the frequency here. Changing the dose won't help matters. We might also want to look at our feeding regime to see if we could adjust the feeding, to, to help things.
If we get a curve like this, that, is apparently doing nothing, and, I think it's important to be aware here that there is a bit of fluctuation, but there is no significant shifts of glucose concentration. Then we're clearly not getting enough effect. And if the insulin dose is greater than 2.2 units per kilogram per dose, then my assessment would be that we are now entering the realm of insulin resistance.
This doesn't stop us. Treating the diabetes with more insulin to get it under control, it just means that we are fighting something else, Cushing's disease, urinary tract infections, pancreatitis, acromegaly in the cat. Something is, is fighting our insulin, and we may need to use more, sometimes a lot more to get that under control.
This is, just show the effect of, that importance of, of twice daily insulin. If we only give it once daily, we will break out. And, and I think a lot of people are worried if they go from once daily to twice daily that they need to reduce the dose.
Because you've demonstrated the, the, the blood glucose is rising, in fact, giving the same dose twice daily is not likely to, to cause any hypoglycemias because you have already demonstrated that you have lost control of the diabetes. Probably one of the most misunderstood phenomenons is that of the insulin-induced hyperglycemia, also known as the samogie overswing. And, and this is a, said to be a situation where we inject insulin, the blood glucose falls rapidly, and hits a hypoglycemia.
Maybe not that long, and then this triggers counter regulatory hormones to resist the insulin, and the dog then stays insulin resistant for some time. The actual truth of the matter is that this is probably not what is happening. Those counter regulatory hormones cannot er er er supplant the insulin so much.
And probably what we're seeing here is simply an insulin overdose being used to compensate. For the fact that the duration of action. Is not long enough.
And in those circumstances, it makes sense to reduce the insulin a little bit and give it twice daily. If you're already giving it twice daily, then still you should reduce the insulin and look at the reasons why this animal may be hyperglycemic in the evening, because often that's linked to feeding. The other thing we see sometimes is animals doing this because they're on pro zinc, and, and they're getting it twice a day.
And it's actually the, the, the glucose that you're seeing going down now is not due to the most recent injection, but the injection before that. some dogs will have odd days when they are insulin resistant for no apparent reason. But there's a lot of accumulating evidence now that the so-called Samogi overswing, the insulin-induced hypoglycemia, does not occur.
And that therefore the correct response to this graph is not to, halve the insulin dose, but merely reduce it by a very small amount and increase the frequency of that insulin. I mentioned a couple of things about skin glucoses and continuous glucose monitoring system. Freestyle Libra's been around for a while now.
It used to come with a little monitor, now it's your, your mobile phone, and it provides 7 to 14 days of data and in many respects this, this is very useful. The problem is that it doesn't necessarily correlate with your blood glucose. And it's important when you put on one of these freestyle Libras to check the blood glucose with a pet tracker or whatever, to, to check that this values that you're getting here are reasonably representative of what the blood glucose values are.
Particularly when the glucose is changing rapidly, there may be a 10 to 15 minute delay between changes in blood glucose and changes in skin glucose. So if at first you get the wrong result, keep an eye on the monitor. It may be that the freestyle catches up with the the, the, the blood glucose value that you just recorded.
The problem I find with these are the same as as blood glucose curves in that one day's data is often overinterpreted. What we really want is an average, and that's what what you've got here, the figures from a dog that has had several days of, of wearing a sensor, and so the average is much clearer there and it's easy to make. Assessments about the fact that this dog probably is, is, is fairly stable, in that it is getting insulin injections, the blood glucose, the glucose is going down, coming back up before the next injection, going down, coming back up, and it is touching nor normal.
It's possible you could slightly increase the the dose here, but actually this is, this is fairly good. Long-term monitoring of diabetics is, is a controversial area with no good answers. In humans, they use hemoglobin A1C.
In the veterinary medicine, we use fructosamines. There's good evidence in human medical science that HbA1c is linked to the risk of complications. There's no such evidence for either this or fructosamine being linked in a to outcome or complication rate in dogs, and that's something that we're all working on.
And, and, and this really is the graph that shows you this, that, the reliability of the history and the physical exam findings for assessing control of glycemia in diabetes is much more about the history and the physical exam than it is about. Blood glucose, of ghost hemoglobin, or a fructosamine. They all have significant issues and overlaps and using clinical history and physical exam to guide you about your interpretation is important.
