Hello everyone and welcome to this presentation on diabetes in dogs. This is the er sister presentation if you like, of one that I gave earlier this year for a webinar vet on diabetes in cats. We're gonna start with a a a quick introduction talking about why dogs get diabetes and how we diagnose them.
And then we'll go on to talk a little bit about that important first consult after we've diagnosed it to discuss with the owners about how we stabilise the the the problem. And then we'll go on to talk about how we get long term survival, and that really reflects how we monitor these these cases long term and how we adjust things, and I'll finish with a, with a brief summary. So let's kick off then with a quick introduction to diabetes and why do dogs get diabetes?
Dogs get a form of diabetes, which is termed type one diabetes, but unlike type classic type one diabetes in humans, which is a disease of relatively young people. Type one diabetes in dogs is something we see in the older animal. And it's, therefore doesn't really sit nicely with a human equivalent, of, of diabetes.
The most common pathology when you look at the pancreas of a dog with diabetes, is that there's been an immune mediated destruction of the islets of Langerhans. This leads to destruction of the islet cells, which means that the insulin production falls. Things like pancreatitis, may also cause damage to the islets, and that may lead to pancreatitis pancreatitis causing diabetes in a very few cases.
But on top of that. Ilet cell destruction. There is often factors that cause the timing of the diabetic problem, to be affected.
So dogs may be, have very few eyelets, but be somehow managing to cope, and then at the last moment, there is something that tips them over. Probably the best example of that is progesterone, in intact, female dogs, you may see, diabetes developing in the immediate post-estro and period. And that's because progesterone is causing resistance to insulin, so the little insulin is there, is now not enough.
Obesity may cause problems, and, potentially things like cortisol, so we see quite a lot of, dogs with diabetes that when you look at them, have Cushing's disease as well. And behind the scenes, probably has been Cushingoid for rather longer than they've been diabetic. Very occasionally, we see it in response to giving prednisolone as well.
Whatever these other factors are, and there are several listed up there, that reduces in insulin production increase sorry, increases insulin resistance, and that leads to that tipping over. And once that tip over point has has happened. And diabetes starts, then you get a phenomenon known as glucose toxicity.
That is to say, as the diabetes gets worse, the ability of the body to respond to insulin goes down. This is counterintuitive in many ways, but reflects the effects of the glucose on the insulin receptors. So that glucose toxicity, it means that once the dog has been diabetic for a while, it probably will become diabetic forever.
So unlike cats, which can go into remission. Diabetes in dogs very rarely goes into remission, and only if you detect it very early and do something very significant with it very quickly will you get these dogs out of their diabetic state. So when we see a diabetic dog, we need to make sure that the owners are aware that this dog's going to require lifelong treatment.
And without stealing anyone's thunder, there's no evidence at the moment that anything other than insulin. Is going to be any use. There is obviously a lot of people talking about other drugs that we might give, but at the moment, every dog that has diabetes needs to be injected with insulin.
And when it comes to diabetes, it is common. It's probably more common than Cushing's disease. It's more common than kidney failure, and it's, therefore considered one of the, the really, really common diseases of, of, of pet practise with about 1 in 200 dogs on your books being affected.
But there are significant breed, sex and age predispositions which will mean that that may not be your experience in your clinic. If you don't have a lot of those types of breeds or those types of, of, of ages of animals, then you're not going to see, see so much diabetes. And I think the diagnosis, we can all agree is pretty straightforward, and where the challenge comes in is having made the diagnosis, how we monitor them, how we stabilise them, and how we keep them well.
This study from the the Royal Veterinary College looking at animals that attended a group of first opinion practises that are part of the Vet Compass network. Shows that actually the survival of diabetic dogs really isn't very good. It, it, it's worse than, for example, Cushing's disease.
it's probably slightly better than renal disease. With about half the dogs diagnosed with diabetes, dying in under 1.5 years.
And rather more worryingly, 10 to 15% of dogs dying at the point of diagnosis. So there is quite a, a significant drop off very early on, and then gradually and chronically over time, there, there, there is a, a fall off as well. And given that renal disease and Cushing's disease tend to occur in that same group of older dogs.
It's interesting that diabetes seems to have a worse prognosis than Cushing's disease, which would suggest that the, the experience with the owners with this disease is, is less good. And one of the main reasons for that is the development of diabetic cataracts. About 2/3 of dogs will develop diabetic cataracts and will do so within the first year.
And this is enough that, you should always warn owners at the point of diagnosis that, their dog is likely to become blind, is likely to need surgery, and will benefit from surgery. So it's important to make sure that owners are aware that this is coming, that the, development of the cataracts is not related necessarily to great clinical control. So as a result of that, they shouldn't blame themselves if the dog does become blind, but they should make sure they've got plans for what they're going to do when the dog becomes blind.
And I think this development of blindness is often a a a prequel to, to the euthanasia decision that will come when these dogs become blind, especially if the owners haven't been warned that this is a likely complication of canine diabetes. It's important just to emphasise the role of breed in the development of diabetes, with breeds like the Samoid and the Tibetan terrier having very much higher rates of diabetes, and the samoid hair is, is, is 15 times 15.2, more likely to get diabetes than the average dog.
Whereas in contrast, interestingly, the box. Is very rarely seen as a diabetic animal. And we, we know that in some breeds, certain haplotypes have been identified and are very common in the development of canine diabetes, and that link in it links incidentally also to a haplotype with hypothyroidism.
So, there, there are significant, genetic elements going on here, leading to the development of, diabetes. The, the diagnosis of diabetes hasn't changed in 100 years. It, it's still essentially a question of an animal that is losing weight.
Polyuric, polydipsic, and polyphagic, or at least is not losing its appetite, starving and urinating in the face of plenty of food, plenty of water. To confirm the diagnosis, if we suspect it, a urine dipstick is the cheapest, easiest, and first and best step to take. But on its own, the presence of glucose in the urine is not diagnostic of diabetes because there are other reasons why animals may get glucose in their urine.
Renal problems, so, tubular deficits, tubular defects, may lead to this, and of course contamination of the sample pot is also, possible. But it's still important to do this dipstick because you can identify things like the presence of ketone bodies or the presence of inflammatory markers that are important in managing the condition going forward. Having identified that there is glucose in the urine, we need to go to do further tests.
What we can say, however, is, is that if you suspect diabetes and there's no glucose in the urine, it definitely is not diabetes. To confirm in the animal with high glucose in the urine, you need to demonstrate high glucose in the blood, and that high is above the renal threshold, which is 10 millimoles in dogs. Most diabetic dogs, or nearly all diabetic dogs will have increased liver enzymes, increased cholesterol.
And yes, they will have increased fructosamines in many instances, but not all. So actually fructosamine as an aid to diagnosis. Doesn't give you very much.
It might be useful for a baseline later. But if you demonstrate high glucose in the urine, high glucose in the blood, you have a diabetic dog, and the fructosamines doesn't, don't matter at all. And this is the evidence for that, and this goes right back to the original paper on fructosamines, which show the concentration of glucose on the on the vertical axis and the Concentration of fructosamines on the horizontal axis, and a group of normal dogs and a group of diabetic dogs.
And you can see here there is considerable overlap in the fructosamine concentrations, whereas the glucose concentrations, there is clear blue water, as it were, between, between the animals that normal and those that were diabetic. So nearly all diabetics at the point of diagnosis have a blood glucose that is greater than 20 millimoles per litre, in this study, and that's been my experience too. So, dogs with blood glucose is less than 10 or more than 20.
So, having made our diagnosis now, what do we, what do we want to do? Well, the, the first and most important thing that we want to do is to sit down and give ourselves some time with these owners. You can't rush it in 10 minutes.
If it takes a double consult, so be it. If it takes a couple of consults over the first week, so be it. If it takes you a little bit of time out of your lunch hour to sit down and give yourself time, then make the time for these owners because you're not going to do it in a, in a, in a quick, quick job.
You need to have plans for how you're going to, to teach them, what you're going to teach them, and get some assistance. The first thing to say about dog diabetes with an owner is if they are, the dog is an entire female, it should be neutered as soon as possible. There is no point trying to stabilise an entire female diabetic.
She will need to be neutered, and then you'll need to restabilize her. The only thing that would stop me neutering an entire female diabetic dog is if that dog was in ketoacidosis. And in that case, one would simply have to treat with the fluids and, and the insulins and so forth and get it stable, but then neuter it.
But everything else, I would put this animal as a matter of surgical emergency to get the source of the progesterone. And the reason for that is that this is the one instance when you can cure diabetes in the dog. And to miss that opportunity to cure the diabetes is, is, is, is wrong.
You really do need to make every effort. To get this dog into surgery to remove the source of the progesterone. Please obviously do not use progestogens and other heat, heat suppressants because that will just cause more insulin resistance.
If you allow the animal not to be neutered, then this dog, every few months, is going to become very unstable, very difficult to manage, very expensive, and will lead to other problems, and may, when they come out, then require big reductions in their insulin as the progesterone wanes. So we really do need to do this. I can't emphasise that too much.
With that one exception aside, there are two things that we then need to sit down. We need a compliant owner. We need an owner who will inject the insulin, can inject the insulin.
And is willing to inject the insulin. And is willing to follow some basic, basic rules about management of their their animal. If they are unable to do this, then this dog really needs to be rehomed.
But most owners can be persuaded to do this. They may not be doing it brilliantly, but they will do it well enough. And the second thing we need is practise support.
And this is a whole team approach. Your nurses need to be involved, your receptionist needs to be involved, and it's important that we are flexible. I, I hate seeing our practise policy on diabetes is that the owners will manage this way.
It, it's completely inflexible. Some owners work shifts, some owners have relatively irregular lifestyles, but these can still manage these diabetic animals quite well if we give them space to be flexible. We need to make sure that the, the monitoring and the targets and the protocols that we're following in this individual patient are well documented, so that we know what what's supposed to be going on.
And that then leads to effective use of our consulting time to make sure that we get the maximum benefit from the consult and that we use things like websites and YouTube videos and all these kinds of things, to augment what we've talked about in the consulting time and. To spend a lot of time talking, talking owners owners through some of the more philosophical or more theoretical aspects of diabetes and concentrate on the really practical points about how we inject and, and so and so forth. But even this can be taught through videos as well.
We do need to allow time to get it right. I typically take half an hour and then my nurse takes another half hour. I have a luxury of working in a referral practise, but I don't think it's possible to do it in much less, to be honest, in, in a primary care practise.
I am not in the consult room for the whole time. I, I, I give the nurse time and space to, to do their, their bit, as, as well, and often the owners will ask the nurse questions that they won't ask me. I always make sure that I've got the person in the room who's going to be doing the injections, not, not another one of the owners or, or something like that.
And I always make sure that I ask the owners about, how much they have got out of the consult at subsequent consults. So I will ask them, did I remember to tell you about hypoglycemia or cataracts? And frequently they, they, they'll tell me that I forgot.
And I know I didn't, but it's a good way of finding out, did you get your message across? Because in a essentially one hour consult, even if it's done in small batches and broken up through the week, the owners on average will take only about 20 to 30% away, with them, if you're lucky. And that is meaning that there are big chunks that you've covered that the owners have heard but not understood or not remembered.
So repetition is really, really important, and checking how much information you're getting over to them is important and giving them other sources of information is important. The websites that I use, generally the ones owned by the insulin companies. They have got skin in the game, for want of a better expression.
They put a lot of money into their websites, and they've been road tested and they work. So those, those would be the ones I would be going for first and foremost. What we need to decide with the owners is what exactly are we aiming for?
And it's easy to say a stable diabetic, but that begs the question of what is a stable diabetic? How are we going to get to stability and how, when we've got stability, are we going to stay there? So, so what do we consider a stable diabetic?
If you send a blood sample to a laboratory, they will talk about a fructosamine concentration as being a measure of stability. If you go to the human literature, it's a glycosylated haemoglobin value. Clinically, it might be an animal that doesn't have ketones or doesn't have hypoglycemic episodes, or an animal that's not losing weight, or an animal that's not got PUPD I think for some people.
It's an animal that doesn't come back, excepted by more insulin and needles, and that's stable. Or have you been to many of these lectures before and think that it's a blood glucose curve like whatever. So it's really important that we decide with our owner, what are we aiming for, what is a stable, what's the end point of us fiddling with the insulin dose, the food, and so forth.
Because if we don't decide that, what will happen is every time this dog comes in, someone will change something, leading to a great deal of owner frustration and confusion. Many of the owners of dogs that come to my diabetic clinic are confused because they've had several different targets, several different comments made about how to get there from different vets. And I think it's really important that we decide where we're going, and it's written in the notes so that subsequent pets can try to follow that as well.
For me, diabetic stability is only a clinical thing, it is not a laboratory parameter. Clinically, what I'm talking about here is an animal that is on insulin treatment. That has no clinical signs of diabetes, that is to say, it has normal body weight, normal urine production, normal thirst, normal appetite.
And we achieve this in dogs by balancing the diet, the exercise, and the insulin, and making sure that the dogs keep healthy. It's important to emphasise that insulin injections are not normal. You and I, if you're not a diabetic, we eat a cake or, or, or eat our lunch, and a little surge of insulin comes up and goes away to deal with it.
And that can happen 10 to 16 times a day. On an average day in the clinic, eating a bit of chocolate here and now again, it might be 20 times a day. Injecting two insulin doses is never going to be close to a normal experience.
It is salvage medicine, for want of a better thing. And, and therefore it is more important to keep the environment regular, to keep the animal fit, to keep the animal healthy so that the insulin can work. About a cystitis or pancreatitis that most dogs would shrug off can be a game changing event for a diabetic animal.
And even with that all in place, dogs can still become blind with their cataracts, and that reflects the fact that we don't really understand quite why dogs go so quickly into their diabetic cataracts. Having decided that what we want to achieve, how we're going to get there, is all about having a routine. If we're going to inject the same dose every day of insulin, then we're gonna have to feed the same amount at the same time, and we're gonna have to feed the same type of food.
We're going to have to exercise in a regular way and we're going to have to keep the environment consistent. But what that routine is, is a matter for discussion with the owner. Some owners, I have one owner who gets up at 5 a.m.
Me, I don't know when 50 a.m. Is, but they get up at 5 a.m.
And they want to inject their dog at 5 a.m. And feed it at 6, and that's fine as long as we know that's what they're doing, we can adjust things.
We can choose our insulins, according to, our, our personal preferences, but we have to be aware that there are two that are, are licenced for dogs and therefore these should always be the first choice in the UK and they are prozinc and Lenty. Lenty insulin should always be given twice daily. Protamine zinc insulin pro zinc.
Can be given once a day, it's licenced for that or twice a day. Can insulin is a pork insulin and is therefore very close to the to the dog insulin in terms of amino acid sequence, whereas prozinc is a recumbent human insulin, and is therefore a little bit different. Both of them use 40 international units per mL, and it's really important to tell owners that you need the syringes with the red tops.
Both of them have red tops and the commercial ones have red tops, not the orange top ones. And I, and I really keep a very close eye on that because it's very easy for somebody to supply the, you know, somebody goes in and says, I want the insulin syringes, and they get the wrong supply. They need to know about this to owners and you need to make sure they get the right ones.
Of course they often can get these insulin syringes cheaper on the internet, and that's fine. I'm not a great advocate of getting insulins on the internet, because of the concern about the the, the, the insulin becoming overheated in the post or whatever and not being looked after, being left on the doorstep or whatever. But, but, some people will do that as well.
Having decided which insulin we're we're going to, to go with, we need to talk about feeding, and in this fortunately, many dogs that are, are diabetic, have a, have a, a, a, a good relationship with food, and so as long. As it's palatable, it, it really doesn't matter so much what is being fed. There are some good studies looking at different diets in diabetic dogs, but the amount of difference they make is minimal compared to the difference if the dog does not eat it.
So what we really want is a diet that that is palatable to the dog, and if that means for the little diabetic Yorkie, that we have to feed it, foie gras with a little slice of chicken and a cube of oxo or whatever, then that's what we're going to have to do. It would be lovely to use a diabetic diet, but if it, that is what this dog is used to eating, then that is OK, that is what we should have to go for initially. We may be able to introduce changes later, later on, but initially we will have to go with what the dog is eating.
It is a rubbish time to try to change the dog's diet at the same time as starting insulin injections. So start with what the dog does. Some dogs are philtre feeders, some dogs will only eat a small amount, and will do so continuously throughout the day.
And if that's the case, that's what you're going to have to live with. You're not going to retrain these dogs to eating 22 square meals a day. Of course, ideally what we want is something that is 2 square meals a day, to go alongside the insulin injections, but it may not be possible.
Then we have to make sure that the total amount being fed is suitable for a dog's energy requirement. And, and that requires thinking about the body weight, about owner factors, about activity levels, about other diseases, about in. Variability with some dogs.
I mean, clearly, Labradors just have to look at a bowl of food and they put on weight, whereas your lurcher can quite happily go, go, and eat bowl after bowl without ever really putting on a huge amount of weight. So clearly we have to think carefully about how much to feed and what to feed, but this is a negotiation with the owner. Having started the insulin, having started the.
The dog, at home, having made sure that it's eating well at home, has got lots of, access to water, then we have to start questioning how we're going to adjust the dose and how we're going to stay on a stable dose. And that all comes down to assessment. And.
The owners are key to that assessment, and it's clear from studies that have been done that many owners vary quite a bit in what assessments they're doing. This is a study from, from America, that it reported 72% of cats were getting blood glucoses done at home. I don't think in the UK that figures anything like that.
But, only 40%, of dog owners were monitoring urine glucose, only 40% were measuring water consumption. Only 35% were making any record of food intake. Only 20% were weighing the dog, and that, I have to say, is disappointing.
We really, That that's a failure of the vets to convince the owners of the cost benefits, the cost savings of good reporting, good recording, and also the ease of doing it, and, and that's something that I'm going to talk a little bit more about, but that's where we are at the moment. So in terms of assessing the dose of insulin, which is mostly what we're worried about, the insulin assessment tools we have available are our history and clinical examination, and that is definitely augmented by good detailed owners' records, as we've been talking about. We've got the option of urine testing for glucose and for ketones.
We've got the option of blood glucose, and that can either be a spot blood glucose or a glucose curve, and we have the option of continuous glucose curves using these new monitoring devices, the freestyle Libras. So those, those are the ones that I consider as insulin assessment tools. Let's deal with these first of all.
History and clinical examination has been shown to have, An enormous impact, done properly, it is by far and away, the easiest, cheapest and best way of telling whether an animal is showing signs of diabetes on insulin or not. And given that we said that the definition of diabetes, stable diabetes is the, all about the clinical appearance, then it's easy to see why that's, that's the case. The problem, of course, with history and clinical examination is that it does not identify the overtreated animal until you have a hypoglycemic episode.
So, I think it's important to do a good history and a clinical examination, but it does not solve the problem of overdose and. It is complicated by owners who are less observant, perhaps because they lead busy lifestyles, or, or because the relationship between the dog and the owner isn't necessarily that close. The, the farm dog that's outside, a lot of the day may not find it so easy to, to the farmer may not find it so easy to record urination, for example.
The next cheapest method of doing this, monitoring is urine testing. And as I, as I see cases coming into my diabetic clinic, I think this is something that many vets seem to have forgotten. it really does work in the sense that it is amazingly cheap.
It is every day. And you can keep going almost ad infinitum on this without causing the animal any problems. If you want to even make it even cheaper for the owner, take one of the urine dipsticks and cut it in half lengthways, and then you get 2 for the price of 1.
And that'll give you, on a pot of this, a month's worth of monitoring for far less than any other form of monitoring. I, I think it's become de rigueur to, to be kind of snooty about urine testing, to put, a urine testing as being somehow, invalid, but actually it, it does an enormous amount, and, undoubtedly it. Gives the owner some sense of control about what's going on and reinforces the pet owner bond, which is also very important in the diabetic life.
And if you want one tip, I, I get my owners to buy themselves a soup ladle. Soup ladles are very good ways of catching urine, particularly in animals like female dogs that go low to the ground. It's quite easy to get under there with a soup ladle, whereas if you try shoving plastic boxes and so forth, they, they're often, you're often getting your hand too close.
So, these are all good tips to, to, to, to get urine testing going, and what's important is these results are recorded. And that you look at them, not on a day basis, but on a weekly basis. So we're looking for the average.
And if you have an average where the urine is consistently glucose uric, then quite likely there'll be a link to a polyurea. There will likely be a link to a polydipsia, and, you will therefore be able to suggest that this animal is unstable. It's important these urine tests are done.
Soon enough after the insulin injection. So if you in the old days they used to give can insulin once a day, and then they'd suggest during the urine test the next morning. And I think that's where a lot of the, the bad reputation of urine glucose measurements comes from.
But that's not a very sensible way of, of using urine glucose testing. If we do it within 12 hours of a urine of an insulin injection, then we're going to have a measure of how much glucose control we've got with the insulin injection. The downside of urine glucose measurements is that you cannot pick up the overtreated dog.
So, on this graph, the, the animals with no glucose in the urine may be either well controlled. Or may in fact be going hypoglycemic. And if they do have glucose in the urine, you don't necessarily know whether it's that the dog's never controlled an insulin resistant or that we are getting an effect of, of the insulin, but that having injected the insulin, the effect has worn off too quickly and we've left the glucose too late.
So the timing of these glucose samples are important, and I encourage my owners to, to, especially in the early time, to take 2 or 3 dipsticks a day. And then we will work out from there what we, what we want to do, because if we are giving can insulin and it's not lasting long enough, then we're going to find we're, we're in some difficulty if we rely on glucose alone, at one point in the day, but if we do multiple points in the day, then we're far more likely to, to, to find out what's going on. Similarly, doing single blood glucose measurements, I often see people measuring glucose in practise, the animal comes in and has a blood glucose because it's a diabetic.
But in truth, one spot glucose, whether it's, it's high or whether it's, it's normal, is probably meaningless because you don't know what's happening the rest of the day. The only thing that you can say is that if ever the glucose is less than the normal, that is to say less than 3.5.
Then you probably are overtreating it. And in which case, you need to back off a wee bit. OK?
But occasionally, diabetic dogs will go into a short hypo and may be the rest of the time perfectly stable. So it's not a guarantee that that you've necessarily got a lack of control, but it's certainly a worrying sign if you've got a blood glucose that's less than 3.5.
Of course that brings us to the question about measuring of glucose and and how good are our glucometers, because most people are measuring these glucoses on glu glucometers. Remember, glucometers are affected by the PCV. They are not as repeatable, as, a normal lab, and there are individual differences between animals on a particular glucometer and between glucometers.
And this is important because these glucometers are gonna affect some decisions that you're going to make. So it's important you check your glucometer in-house. You need to keep an eye on what your glucometer is doing.
If it comes with a control solution, use the control solution. If it doesn't, then do check the glucose on the glucometer versus another method such as a reference laboratory. As you see from this correlation graph between 11 glucose glucometer here and a reference measure, there can be significant bias in these machines.
Some of them are good, and I'm not dishing all glucometers, but you do need to know your glucometer. Glucometers are probably more effective when used to create a glucose curve. And when we do that, then we're, we're going to, to look at these, these animals, not as just having one spot check, but several spot checks.
And those spells are drugs that we will therefore create a pattern, and it's the pattern that's important here as much as anything else. So this is a, a sort of standard, glucose curve chart that we have here, and you can see, see that we've got, an insulin injection being given once here, and two feeding episodes. And when you look at a stable diabetic dog, this is the kind of curve that you will get.
Which is to say The insulin does not work immediately. It takes a while to work, to kit in kick in. The food, on the other hand, tends to work quite quickly, so that there can be a lag between the two.
The glucose will then go down, but will rarely enter the normal zone. We're not looking for normality here. And when we give another food, then the glucose will start to rise again and eventually break through the renal threshold, and that'll produce a small amount of glucose in the urine.
And that's a, a, a once day injection. It's not great, but it's, it's a, a, a good philosophical concept that we don't want this, glucose going into the normal range, and we do want to expect some fiddling around between the insulin injection and the food to get that right. It's important to not to emphasise to owners too much about feeding, then injecting.
For some dogs, injecting, then feeding is going to be better for that dog. It depends on the rate of onset of the insulin, and to some extent, injecting then feeding gives the dog a reward for behaving during the injection. How good are blood glucose curves?
Well, there's a, there's quite a bit of debate about this. These, these, charts have been around for years, and many people think that this is what we're aiming for. But the reality is that if you repeatedly do blood glucose curves, such as, such as here, we have, we have, 22 glucose curves, one in dashed and one in, one in a solid line here.
that, that we repeatedly do them, that we get different results. this just to orientate you, these are American units, I'm sorry, but you see the normal range here in the thick grey line and the thin grey line is the renal threshold. So 200 milligrammes per deciliter is about 10 millimoles per litre.
And you can see here that we've got two curves, one you'd suggest probably is well controlled, the other probably not. Similarly, another two curves here, both, reasonable control, perhaps the dash line might might alter your thinking about insulin timing and, food timing. And here, another, another pair of curves with clearly the solid line being a diabetic that is not well controlled, whereas the dash line possibly is.
. I think it's worthwhile emphasising this is the same dog coming into a hospital, having two curves down each time, 1 week apart, with no change in insulin, dose, timing, exercise, or food. What this study showed was that the day to day variation in blood glucose curves in healthy diabetic dogs is enormous. And when we start to look at some continuous glucose measurement data now, we can see this coming through as well.
These dogs are not stable every day. We're only aiming for average stability. And one of the reasons why we get ourselves into problems is to forget that if we take a normal glucose curve in a diabetic dog and we stress the animal, then we will produce a significant insulin resistance, and that stress may simply just be going into a hospital and spending the whole day listening to a young puppy barking.
So blood glucose curves in the hospital are not a great idea, and they are pretty expensive. Blood glucose curves out at home are less stressful for the dogs, assuming that the owners can manage it, and certainly help the owners feel in control of the situation. Problem is they're not for every owner.
Some owners are, are, are very reluctant to do this, very unable to do it, they squeeze too hard, they cause problems with the, the, the, the, the, the sample quality that they're getting, and the general impression is that there's actually no overall increase in, in, quality of life or duration of life. So enter stage left, the new continuous glucose monitoring systems. Now these have all been around for many years, but they were very, very expensive, they were cumbersome, they were too heavy, they were, all sorts of problems, but the new freestyle Libras which we have now, which measure.
the glucose in the interstitial fluid. I, I like to explain this to owners as measuring the skin glucose, not quite true, but it's, it's close enough, rather than the blood glucose, the, the skin glucose. The, these are real, real, have been a, a, a, a big game changer.
It's important to remember it's not blood glucose, and that means that if you take a blood glucose sample and you look at your freestyle Libra and you get a different result, do not be surprised. It will take 10 to 15 minutes to equilibrate. And therefore, when you have situations where the glucose is changing rapidly, there may be very significant differences.
Sometimes these continuous glucose monitoring systems are simply inaccurate. They are off far too much. They, they are not that cheap, they're certainly cheaper than doing blood glucose curves, but they're not that cheap, especially if you're going through quite a few sensors, trying to keep the, keep them on.
unlike older versions, there's no need to calibrate, but that doesn't mean to say you shouldn't check. So when we have these animals with these freestyle Libras, we do like to do a blood glucose and check that we're close, and if we're not close, then we check again a couple more times. And if we're still not close, then we start to distrust the data.
These data, these, these devices last 7 to 14 days, and, and I think my big problem with them is, is it leads to data overload. The number of curves, the number of interpretations, how you do, what you do, when you do, what should we do. It's all still to to be decided, and it is hard to know how to interpret these curves, on a day to day variation.
So when you start to see the the these curves and you start to try to interpret them, you, you, you, you can start really going down a bit of a, a, a rabbit hole. Here, you know, there, there are, there, there's, there's dogs here in, in the, on the bottom there that are clearly not responding very well to the insulin. And then the dog on the bottom left is clearly responding.
We've got some really fast swings in glucose from hypo to to hyper, and then some that are more consistent. These are all the same dog. These curves were all taken from the same dog.
Different doses of insulin playing around and so forth, but they fluctuate enormously. We can have day to day variation that is at least as much as this, and that just emphasises what we saw in the blood glucose curves, is that a day to day analysis of What's going on is not that useful, because there are days when they are unstable. What is useful from the freestyle Libra, is the average curve.
And where you get average curves that look like this, then you feel a lot more confident that you actually have a dog that is not going hypo. That isn't going very hyper for consistent periods on a, on a regular basis. It may have odd days when it's bad, but the majority of it is good, and when it's like this, then, and I can look at this and say, I don't want to as long as this dog is stable, I don't need to adjust this.
Now if this owner came in and said, my dog is urinating at night, because it, and the glucose is high then. Then what we may do is postpone the injection to slightly later. So for example, we may inject at 6 o'clock in the morning, but at 9 p.m.
At night, in order to, to, to get it through. This is how you can interpret these, these things to help the owner see, see a way through. We certainly had one dog that was on 3 times a day peninsulin.
We've switched dogs like this from can insulin to pro zinc on the basis of this kind of data. All this is helpful data, but it is important to look at the averages, not the day to day. It's also important when you're putting these devices on owners to make very, very clear to the owners, you must not intervene unless the dog is actually hypo, clinically hypo, i.e.
Is barking, is excited, is upset or whatever, then you must not intervene. We have owners who will give extra doses of insulin, they give food and so forth. And of course that completely messes up the averages and the ability for us to know what exactly is going on.
What about long term survival? What, what matters there? We've talked about adjusting the insulin and of course insulin adjustment tools are very important for, for assessing whether we're going to change the, the, the, the insulin or not, or the food or whatever, but how do we know how we're doing?
And, and I think that on this longer term measures of diabetic stability are important. But they are not of themselves, things that you should use to decide whether to change the insulin. You need the other things, the clinical history, the urine tests, the blood glucose, and the continuous glucose monitoring tests to make that assessment.
All fructosamines and haemoglobin A1Cs do is tell you how well you're doing. It's your score at the end of the month, if you will. For a long time now, I, many of us have been wondering whether fructosamines are the best method of assessing control in the diabetic patient, because the evidence is pretty weak.
If you go back to the original research publication on fructosamines, Claudia Rausch divided up her diabetics into those that were fully satisfactorily controlled, moderately controlled, and poor controlled, and measured their fructosamine. And clearly there was a big overlap. There was a clearly a a large number of these cases had the same fructosamine concentration, regardless of how well they were controlled.
And by control, our definition of that was clinical. So unless the fructosamine is absolutely massive, but in which case the dogs probably have fairly significant clinical signs anyway, of instability, the evidence that fructosamines are the best way of assessing diabetic control is really rather weak, and, and frankly, if you want to save the owner's money, stop measuring fructosamines. In human beings, haemoglobin A1C has replaced fructosamines years ago, and that's because it's a longer measure.
It, it, it is a measure of the glycosylation of haemoglobin, and because haemoglobin lasts longer in the circulation than albumin, which gives you your fructosamines, so this is a better long-term measure. And they know that there is a link between the haemoglobin A1C concentration and the development of neuropathies, retinopathies, and so forth. So, if you are a stable human diabetic or an apparently stable human diabetic and your HbA1C is 10%.
They actually need to do something about that. They will have you back into the diabetic clinic to say, look, we need to go through this again because we're, we, we're concerned that you're going to end up with complications. We know that we can measure HbA1C in dogs, but sadly, the machines that were used in many of these early studies are no longer available and often because they're not accurate enough and reliable enough for normal clinical use.
Enter the Siemens DCA vantage analyzer, which is a human machine that runs a latex immuno immunoglutination inhibition method, which turns out to work very well for dogs. And we've been using this now for more than 10 years, as a, as a measure as a way of measuring haemoglobin A1C. The reference range is 9 to 18, and I'll start off by saying right at the moment, I've never had a diabetic get anywhere near close to the reference range.
generally my stable diabetics are somewhere between 18 and 25 to 30, and the unstable ones are over 30. But that's just a clinical impression. We need to back that up with some science.
So we've had a project running at Glasgow now for about 8 years, funded by BSAVA pet savers, looking at whether HBA1C can be used to predict outcome, because if it can, Then that would mean that if it was outcome mediated, then we could would adjust our management of the diabetic, and it not just change the insulin dose, but the overall management, on the basis of increasing HbA1c results. Those results have still not been published, we've got probably about 3 or 400 measurements of HbA1C now, and we need to do some decent number crunching. There are some limitations to HbA1C because it's haemoglobin, anaemic patients will have abnormal HbA1cs.
There can be some interferences with bilirubin, so jaundice patients, and those with high triglycerides. Early changes in diabetic stability are not detected, and it's definitely not a tool for the diagnosis of diabetes. And finally, significantly, given that our population at our diabetic clinic HbA1C cannot be used in cats because cats, unfortunately, are just different.
They have a different amino acid sequence at the site where they would be glycosylated and they're not glycosylate. There is some evidence from the clinical and history taking paper that neither blood glucose concentrations nor fructosamines, nor HbA1cs can be used to distinguish between the good and poor control of glycemia. So this is not an immediate assessment.
This is about looking forward, looking at the prognosis in the future. You've got to be careful not to use these to influence your clinical decision making about what you're going to do, merely at the moment that if it's high. Then we need to look at the overall picture, and see how things are there before we make any decisions.
And the assumption would be that animals with a high fructosamine or a high HbA1c that cannot be controlled, have a worse outcome, but this is still to be tested. And that's that data showing, showing that, the glycosylated haemoglobin, which is, close to HbA1c, and fructosamine, do not actually, tell you the difference between control of glycemia that well, with significant overlaps, between the good and the poorly controlled. So as we come to the end of that, let's try to draw this into, into a summary about how we should stabilise diabetics.
we should stabilise. I would always start a dog with twice daily insulin, using can insulin, a lenty insulin, but if the dog was difficult to manage in some way or the owner's very reluctant, I might start on a pro zinc insulin once daily, but lenty insulin twice daily would be the best place to start. And if we couldn't see the dog again and we weren't going to do very much, then a minimal stabilisation would be to get the owner monitoring the urine and then adjust the insulin according to the average of the morning urine tests.
My standard stabilisation is essentially that, but in, in to add to that, we have a diabetic scoring system, the RVC give you, give you one online, we, we use a form based thing, but it's basically a scoring scheme to try to assess the ability. We look at the morning urine test, but we do also add in blood samples. Looking at spot glucoses, fructosamines, HbA1Cs, to see how they're changing, and definitely the clinical findings are the most important, and they're the ones that cha allow me to, to change the insulin dose.
The others are just telling me how much I can change the insulin dose by. And then, and this is where perhaps more different, is once they're stable. Then, then I will stick on a continuous glucose monitoring system to check how good my stabilisation.
If they're clinically stable, I'm not going to alter too much, but I do like to see that, and that that's my sort of standard approach to these things. In some instances, owners want a quick stabilisation, or we want a quick stabilisation, or they're very keen and very able. In those instances, I will do all of the above, but I will stick on a freestyle Libra, and I will change the insulin dose every 2 or 3 days in a more aggressive fashion if need.
Because I can see in real time what's going on, and therefore we can adjust the the the the dose. And what's more, we can then check stability for two days using that continuous glucose monitor and just to make sure that everything's fine. So that's a more sort of aggressive and advanced way of doing, but obviously it's more expensive.
Do I think that it's better than the other methods? No, I don't, but I think it is quicker. Just a plea, it's not just a diabetic recheck, it's, it's a really important point in this dog's lives.
When you see an animal coming in for a diabetic check, ask them for their home records, get used to that question and you will be rewarded by owners bringing you in detailed records. Urine glucose, ketones, records of urination, thirst, appetite, ask about hypoglycemic episodes, weigh the dog every time weigh the dog. Insulin is the bodybuilding hormone of the adult animal.
Check the eyes for those cataracts. Early recognition of cataracts means that you can warn the owners. Early recognition of cataracts is also good if you're going to go forwards with some sort of surgical procedure to remove those.
Biochemical assessment, very low on the list. Ryptosamines even lower. Most importantly, during a diabetic recheck, your job as a veterinary surgeon is to encourage the owners.
That's the single most important thing that these owners need is to encourage them to keep on injecting and use the diabetic recheck to repeat messages, repeat messages about what a hypo looks like, repeat messages about cataracts, even if they haven't got them, repeat messages. Diet and not drifting off the diet, repeat messages about flexibility and so forth. These are all important messages to repeat, to get that educational piece over with the owners.
Don't assume they remembered it from 1 or 2 or 3 years ago when you first did it. So in summary, diabetes shouldn't be complicated. This is complicated.
This is the Large Hadron Collider at CERN in Switzerland. This is complicated. Diabetes, you've got to keep it simple in order that the owners feel empowered to look after their dogs better.
If you make it complicated, if you make it difficult, you are more likely to lose your patience. OK, I hope that was useful. I'd be happy to take any questions.
My email address is up there, and I, I'm quite happy to receive requests for email advice, but please don't send me 1000 freestyle Libra graphs and ask me to interpret them, because obviously, they, they, as we said, it's all about the averages. Thank you very much for listening.