Hypoglycemia trips veterinarians up in a number of ways. It has a variety of causes and some can be more challenging to pinpoint than others. In this episode, Veterinary Medical Internist Dr. Andrew Woolcock joins Dr. Andy Roark to discuss the case of a young hypoglycemic yorkie, before expanding the conversation to discuss hypoglycemia in general.
This discussion covers causes of hypoglycemia, appropriate diagnostic workups, and practical treatment approaches.
You can also listen to this episode on Apple Podcasts, Google Podcasts, Amazon Music, Soundcloud, YouTube or wherever you get your podcasts!
LINKS
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ABOUT OUR GUEST
Dr. Woolcock is a veterinary internist. He’s from the Midwest and did his schooling at Michigan State University, where he graduated with his DVM. After an internship at North Carolina State University, Dr. Woolcock completed a residency in small animal internal medicine at the University of Georgia. He joined the faculty at Purdue University in 2015, and is currently an Associate Professor of Small Animal Internal Medicine. Dr. Woolcock loves the complex puzzles that internal medicine patients present, and loves working with students as they put the pieces together. He loves all-things-medicine, because physiology is so fascinating, but he especially gravitates toward immune-mediated diseases and endocrinology. Dr. Woolcock enjoys his clinical practice, but also his research in oxidative stress, and the scholarship of teaching and learning. When he’s not at work, Dr. Woolcock is likely watching old movies with his husband and their dog, Auggie (not sure of what breed he is, so they invented one for him – a Miniature Fluftoffee).
EPISODE TRANSCRIPT
This podcast transcript is made possible thanks to a generous gift from Banfield Pet Hospital, which is striving to increase accessibility and inclusivity across the veterinary profession. Click here to learn more about Equity, Inclusion & Diversity at Banfield.
Dr. Andy Roark:
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Dr. Andy Roark:
Welcome everybody to The Cone of Shame veterinary podcast. I am your host, Dr. Andy Roark. I am back with internal medicine specialist, Dr. Andrew Woolcock, and we are talking about hypoglycemia today. We first start and talk about a little itty bitty young dog that has it, and then we go into the other reasons that you see patients that have hypoglycemia. This is a great short, to the point overview of a very common condition that can come from a lot of different places, so guys, again, I love this. This is one of those pearl episodes where you just breeze through it. It’s only about 15 minutes of actual interview, and you’re just going to get a lot out of it in a short amount of time. Again, thanks to Dr. Woolcock for being here. He’s amazing. Gang, let’s get into this episode.
Kelsey Beth Carpenter:
(singing) This is your show, we’re glad you’re here, we want to help you in your veterinary career. Welcome to The Cone of Shame with Dr. Andy Roark.
Dr. Andy Roark:
Welcome to the podcast, Dr. Andrew Woolcock. How are you?
Dr. Andrew Woolcock:
I’m doing very well. Thank you for having me.
Dr. Andy Roark:
Oh, man, my pleasure. I love having you on the podcast. You are, for those who don’t know, an internist at Purdue University’s College of Veterinary Medicine, residency at University of Georgia. You have been on the podcast not too long ago talking about, oh gosh, what did we talk about? IMHA.
Dr. Andrew Woolcock:
Yes.
Dr. Andy Roark:
Yes. It’s been so long it just disappeared from my brain. I wanted to get you back. I’ve got a case I want to talk to you about, and it’s sort of a general, general subject matter. Let’s just start with the case. I have got a young, like eight-month-old Yorkshire Terrier male, neutered, named Taz, and he is not looking good. He’s lethargic, trembling. Owners are really freaking out. He does not look like a normal happy, healthy dog. I did a little bit of blood work on him and the main finding that I have is hypoglycemia.
Dr. Andy Roark:
His glycemic index is low. His glucose is down there. I just wanted to go ahead and ask you about this. As I’m looking at this little dog and thinking okay, what am I looking at here? Why does this happen? I just want to make sure I’m not missing anything. Mom and dad are like what does this mean for the longevity of our dog? Is this dog defective? Did we get a lemon? All of those sorts of questions that you might have if your eight-month-old dog just suddenly stopped working. How do you treat that? Let’s go ahead and start to sort of set this up. What do you think about when you see hypoglycemia in a young dog?
Dr. Andrew Woolcock:
Yeah, so I think thankfully their young dog has not stopped working. It’s just that their young dog is working really hard and has a really rapid metabolism that needs a lot of glucose all the time to keep things running. In very young, very small breed dogs, think like hummingbird metabolism. We’re talking small, so things are moving quickly, so these are the breeds and at the age where they just need frequent access to food to be able to keep their glycemic index up.
Dr. Andrew Woolcock:
The reality is maybe this family’s been feeding the dog the same way, and ever so slightly this dog’s been really holding steady right at the cusp of being hypoglycemic and then skipped a meal, missed a meal, ate a little less, something like that, and that’s why the dog looks like it in this moment and they’re freaking out. Thankfully this is hopefully a very easy to address issue for this Yorkie, and you’re probably going to end up doing more client care in this scenario to help them understand that this is a problem that is very addressable and fixable.
Dr. Andy Roark:
Okay. I have a lot of Yorkies that are small and they stay small. Is the fact that I see this in young dogs, is that attributed to the fact that their metabolism slows down as they get a little bit older? Is that why I’m not seeing this in four and five-year-old Yorkies?
Dr. Andrew Woolcock:
I think it’s a combination of things. One is sure, yes, as they age their metabolism changes, but also when they are very young, their machinery to store glucose in the form of glycogen, their liver to respond to all the different hormonal influences that can regulate glucose nicely, their fat stores and muscle stores, which are a huge storage for energy, are just not quite as robust as they are once they’re at their adult size. They don’t have all the other machinery in place yet to kind of keep them balanced like they do as they reach adulthood.
Dr. Andy Roark:
Talk to me about how the presentation here is going to differ, how my thought process is going to differ when I’m looking at this eight-month-old dog versus when I’m looking at a six-year-old dog or a 10-year-old dog. Hypoglycemia presents for a number of different ways. Help me get my head around that. Let’s just jumping ahead and looking at other patients. What am I looking out there? What are my differentials? Just start to unbox the metabolic phenomena of hypoglycemia for me.
Dr. Andrew Woolcock:
Sure, yeah. I think at its very stripped down level you can think about hypoglycemia as being caused by one of three very broad categories. It’s either going to be insulin related, and we can talk about that separately, but it’s either going to be an increase in insulin, whether that’s naturally occurring like an insulin secreting tumor or something like that or it’s your classic diabetic dog who was given too much insulin. Either that hypoglycemia is related to insulin specifically or they’re hypoglycemia either because they have something that needs more glucose than they’re providing it, like in sepsis or with certain tumors or something like that, so there’s an increase in utilization of their glucose, or there’s a decrease in the production of glucose.
Dr. Andrew Woolcock:
That can come in your neonatal Yorkie that we were just talking about, very young where they’re just not eating enough, or other things that can cause a decrease of production of glucose are things like liver failure, since the liver is so integral to glucose metabolism, or even things like Addison’s Disease because we know that cortisol is a counter-regulatory hormone, basically does the opposite things of insulin. It is there to help continue the production and storage of glucose. In Addison’s Disease where you’re cortisol deficient, hypoglycemia would be a common presentation. Then certainly toxins and things can manipulate glucose as well.
Dr. Andy Roark:
Okay. What does your sort of general diagnostic workup look like for an older dog that comes in, main presentation is hypoglycemia?
Dr. Andrew Woolcock:
Yeah. I think if it’s an older dog presenting with hypoglycemia, maybe you find it just on your alpha track or bedside blood glucose, so that’s the piece of information you have. The best next thing to be doing is full lab work because on a CBC you’re already going to be able to identify let’s say a really severe inflammatory leukogram, maybe left-shifted toxic changes to your neutrophils that are going to move you in the direction of the septic cause for that hypoglycemia. On your chemistry profile maybe you’re going to see changes that would indicate liver dysfunction or maybe you see electrolyte changes that push you towards an Addison’s diagnosis and things like that.
Dr. Andrew Woolcock:
Really, those pieces of blood work are going to be extremely helpful just to start moving you in the direction of which of those you’re dealing with. Then I think if you’re not finding evidence on CBC or chemistry to move you in the direction of toxin, sepsis, Addison’s, liver disease, then just make sure you’ve got some serum saved that you can test insulin levels on that serum because a paired insulin/glucose ratio is the way to start thinking about insulin secreting tumors or something like that. I don’t think I would ever do that straightaway, but one of the pitfalls I see people run into is that by the time they start thinking about testing serum for insulin, they’ve already given the dog a bunch of dextrose and they’ve already supplemented, and they’ve already manipulated the whole glycemic index, and then it becomes a lot more difficult to test for that or evaluate that, so just make sure you save a little bit right at the beginning when you’ve got that hypoglycemic pet.
Dr. Andy Roark:
That makes sense. Hey everybody, I’m just jumping in with two lightning fast updates. Number one, if you have not gotten signed up for the Get (beep) Done Shorthanded virtual conference in October, it’s October 6th through the 8th, you need to do that. If you are feeling overwhelmed in your practice and you want things to go smoother and faster, if you do not want to watch webinars, you want to actually talk about your practice. You want to do some discussion groups, you want to do some workshops where you actually make things and work on things and ask questions as we go along, and have round table discussions and things like that that’s really going to energize you and help you figure out actionable solutions that you can immediately put into practice to make your life simpler and more relaxed, I got you covered, buddy.
Dr. Andy Roark:
But you don’t want to miss it. Go ahead and get registered. Mark yourself off at the clinic for the time so that you can be here and be present and really take advantage of this. I don’t want it to sneak up on you. I know October seems like a long way away. It’s not. But go ahead. I’m going to put a link down below and then when registration opens we’ll let you know it’s open and you can grab your spot. But you do not want to let this sneak up on you.
Dr. Andy Roark:
Check out our Get (beep) Done Shorthanded conference. It’s going to be a great one. This second thing I’m going to tell you about is Banfield. Thank you to Banfield Pet Hospital for making transcripts of this podcast available. You can find them at drandyroark.com. They are totally free and open to the public and Banfield supports this to increase accessibility and inclusion in our profession. It’s a wonderful thing that they do. Guys, that’s all I got. Let’s get back into this episode. Let’s talk about emergency presentation of hypoglycemia. How aggressive do you get on this? Where are your levels? Where do you go from a one alarm fire to a two alarm fire to a five alarm fire?
Dr. Andrew Woolcock:
Yeah. I think your one alarm fire is maybe the young Yorkie, Taz, that you presented at the beginning, who presumably has an appetite and whose hypoglycemia so far is presenting as yes, the dog looks rough but he’s just lethargic and not acting himself, and so as long as he seems neurologically with it and normal mentation, then in that dog, the emergency stabilization may be as simple as let’s offer him a food that has a high glycemic index, high calorie, and get him eating.
Dr. Andrew Woolcock:
I do not think that every hypoglycemic patient, even in the ER, I don’t think every single one needs immediate dextrose bolusing and things like that because in fact, sometimes that kind of messes with the system a little bit and causes insulin surges and all these things that you aren’t intending. If you have a patient that has a normal mentation and has an appetite and wants to eat, whose hypoglycemic signs are mild, food may be all you need in the emergency stabilization.
Dr. Andrew Woolcock:
But that two, three, five alarm fire, those are going to be the patients that really present with some severe neurologic side effects from their hypoglycemia or have already suffered a hypoglycemic seizure, whether they do that in your clinic or they come in postictal. That’s going to be a patient that you aren’t going to really want to rely on consuming food, because that may not be safe for them and that’s where dextrose supplementation becomes key.
Dr. Andy Roark:
Let’s talk about that. Any words of advice, guidance, on dextrose supplementation? I always have a little bit of panic as I’m getting ready to give IV dextrose and always go, “I want to make sure I do this just right.” Give me some pearls on doing a good job in dextrose supplementation that are going to get me the results that I want with the lowest stress on me and the team.
Dr. Andrew Woolcock:
Yeah. I think that thankfully this is a medication that is readily accessible in most clinics and has a very wide safety margin, so you can feel good even if you can’t remember the dose and you’re scrambling, and you’re looking around, give some and you’re fine, but a great general rule is half a mil to one mil per kg of 50% dextrose is a wonderful place to start as a bolus. Then something that I think would help a lot of clinics so that they’re not in that nervous state between boluses of how are they going to handle this, is their glucose just going to drop again, how often do I need to be checking, is once you’ve identified that they need a dextrose bolus, then it’s very reasonable to start them on a constant rate infusion of an IV crystalloid.
Dr. Andrew Woolcock:
Start them at a maintenance fluid rate or higher if you think they’re dehydrated, and add dextrose to those fluids. We often start them on 2.5% dextrose because then at least you know that you can attend to other emergencies that come into your clinic, things like that, and you’re not going to be feeling that anxiety about are they just going to plummet again and am I going to miss it? Are they going to have another seizure? When do I need to reach for another bolus? Starting them on a CRI gives you a push-in to then recheck, and the 2.5% CRI that you start may not be enough and maybe you’ll increase that over time, but I think that’s a nice way to continue to address the problem while you’re realistically waiting on maybe that CBC chemistry to be performed or things like that.
Dr. Andy Roark:
Right. That makes sense. I’m assuming that the amount of time that we’re going to have them on a CRI treatment schedule is probably going to depend largely on what we decide the underlying cause is. Correct?
Dr. Andrew Woolcock:
Yeah, absolutely correct. I think if this is a patient who you do ultimately identify as septic, and now you’re searching for a source of sepsis, then they may remain on some kind of dextrose supplementation for awhile as you identify that septic source, but if it’s a dog who ate something that had xylitol, an artificial sweetener that causes hypoglycemia, then maybe they just need their supplementation overnight while you deal with the toxicity and get them through a shorter period. I think it really just depends on the cause.
Dr. Andy Roark:
Say that we’ve got that dog that ate xylitol, or we’ve got that dog that’s been septic, and we’ve been treating with antibiotics and we feel like the patient’s getting better and starting to eat again. Do you look at the patient and say he’s looking pretty good at this point or do you use diagnostics to guide you as you withdraw dextrose supplementation?
Dr. Andrew Woolcock:
I think probably a combination of both. I think absolutely clinical signs are going to be the biggest part of it, but certainly once you’re making the decision to stop dextrose supplemenation there’s going to be a window of time between stopping it and them getting low enough to show you anything clinically that you would love to see that trend before you allow them to get lethargic and seizuring and things like that.
Dr. Andrew Woolcock:
Monitoring blood glucose is going to be important and something that we have started doing more of for people that are doing this or may not be familiar, are using interstitial glucose monitors. Those are like the FreeStyle Libre, something that can be placed on the skin that can measure the glucose in the interstitium and it saves you from having to poke or draw more blood or things like that. If you’ve got that patient who you think this is going to be a long-term issue that can be really helpful in the hospital.
Dr. Andy Roark:
Yeah. That’s super cool. That’s not something I’ve gotten to try yet, but I think that’s pretty fantastic.
Dr. Andrew Woolcock:
Yeah, and obviously the accessibility of small capillaries to use a glucometer are very easy, but those patients that are very small, that you’re finding yourself drawing blood four or six times a day and you think gosh, I’m a vampire at this point I’m taking so much blood, it’s a really nice way to sort of move away from the blood product and be looking at the interstitium.
Dr. Andy Roark:
What are the pitfalls? What are common mistakes? What are things that trip up doctors, technicians, when we start talking about hypoglycemia?
Dr. Andrew Woolcock:
Yeah. I think that to me, probably the biggest pitfall is to get too much tunnel vision about how critical the acute phase of hypoglycemia is and therefore assume that the underlying cause must also be quite severe, because I think a lot of times people worry. In the Yorkie, the young Yorkie, people feel at least comfortable with that setting, but the dog that comes in that’s unexpectedly hypoglycemic, I think it’s natural to assume that they may be septic or have an infection and it may be natural to reach immediately for antibiotics and hope that you’re going to clear it up that way. I think one thing I just encourage people to do is take a step back and really make sure that the remaining blood work you do continues to support that assumption of critical disease because in a lot of cases it doesn’t.
Dr. Andrew Woolcock:
You can start to suspect something less concerning or something that is not necessarily critical like a septic patient and maybe that starts to take you down the pathway of Addison’s Disease or maybe starts to move you towards an insulinoma, which of course is still not a great diagnosis, but is one that you can take a little bit of time with to assess and to start to think about imaging and things like that. I think the biggest advice I would have is to not just assume hypoglycemia means infection and make sure that the rest of your evaluation supports that if that’s where you’re headed.
Dr. Andy Roark:
That makes total sense. Are there any other resources that you would point people towards, anything, I just sort of think of nutritional management, things like that, that you’ve found particularly valuable?
Dr. Andrew Woolcock:
I would not say not something specific for hypoglycemia. However, I think nutritional management or nutritional textbooks are really good to have and then also even a clinic that doesn’t have an ER component to their clinic, having some kind of critical care textbook, whether that’s physically or an eBook version, are really helpful for those settings where your a day general practice and you’re hit with a true emergency situation, and you’re going, “Gosh, I don’t remember what the stabilization plan is for this or the dose for this drug that’s in my crash cart that I never use,” stuff like that. I think making sure you’ve got that resource available is great.
Dr. Andy Roark:
That’s awesome. Andrew, thanks for being here. I really appreciate it.
Dr. Andrew Woolcock:
Sure thing. Thank you.
Dr. Andy Roark:
And that’s it. That’s what I’ve got for you guys. I hope you enjoyed it. I hope you liked the episode. If you did, if you’re watching on YouTube, hit that subscribe button. If you’re not, wherever you get your podcasts, if you’d love to leave us a little review that means the world to me. Yeah, if you like learning, check out the drandyroark.com website and take a look at our store. We’ve got some training tools. I have a Charming the Angry Client course and an Exam Room Communication Toolkit course. Both of them are on demand. Both of them are very, very good. They are both very flexible and they are a great way to learn with your team. Guys, until next time, take care of yourselves. I’ll talk to you later on.
