Veterinary cardiologist extraordinaire Dr. Kristin MacDonald teams up with Dr. Andy Roark to debunk the myths and unravel the legends swirling around cardiology. From heart attacks in dogs to the controversies surrounding grain-free diets, they dissect it all. Tune in as they sift through the maze of modern ideas floating on the internet, separating fact from fiction, and shedding light on what holds true in the world of pet heart health.
This episode is brought to you by CEVA Animal Health!
Important Safety Information: Do not administer in conjunction with non-steroidal anti-inflammatory drugs (NSAIDs) in dogs with renal insufficiency. Do not use in dogs with hypoadrenocorticism (Addison’s disease), hyperkalemia or hyponatremia. Do not use in dogs with known hypersensitivity to ACE inhibitors or spironolactone. The safety and effectiveness of concurrent therapy of Cardalis™ with pimobendan has not been evaluated. The safety of Cardalis™ has not been evaluated in pregnant, lactating, breeding, or growing dogs. Cardalis™ administration should begin after pulmonary edema is stabilized. Regular monitoring of renal function and serum potassium levels is recommended. Common side effects from a field study include anorexia, vomiting, lethargy, diarrhea and renal insufficiency.
LINKS
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ABOUT OUR GUEST
Dr. Kristin MacDonald earned her doctorate of veterinary medicine in 1998 from Auburn University, and then completed an internship in small animal medicine and surgery at Michigan State University in 1999. She finished a residency in veterinary cardiology at University of California, Davis in 2001 and became a board certified veterinary cardiologist in the American College of Veterinary Internal Medicine in 2002. She continued her education by earning a PhD at UC Davis Comparative Pathology graduate group in September 2005 on hypertrophic cardiomyopathy in Maine Coon cats, and the effects of ACE inhibitors. Dr. MacDonald taught on faculty at UC Davis for a year, and then became the clinical cardiologist at the VCA Animal Care Center of Sonoma County in Rohnert Park, CA, where she continues to have a busy cardiology practice. She has been an active author of book chapters for highly respected textbooks, served as section editor for Handbook of Small Animal Practice, published a multitude of original research papers, and is coauthor of The Textbook of Feline Cardiology, the only text of its kind available. Dr. MacDonald has participated in clinical trials involving treatment of canine congestive heart failure, and enjoys being the lecturer for the VCA Cardiology Series in the United States. Living in Sonoma County, she enjoys spending time outdoors hiking, skiing, and being mom of two daughters, two Tonkinese cats and a Labrador Retriever.
EPISODE TRANSCRIPT
Dr. Andy Roark:
Welcome everybody to the Cone of Shame veterinary podcast. I am your host, Dr. Andy Roark. Guys, I am here with veterinary cardiologist, Dr. Kristin MacDonald. Today we are talking about cardiology myths. We are walking through a little bit about heart murmurs, a lot about heart failure, a lot about communicating the heart failure to clients, a lot about managing heart failure. We talk a bit about Spironolactone and why it has become so popular in cardiology and it’s all sort of presented in the format of myths and legends that I have heard and mostly I’ve seen online with pet owner groups, things like that, pet owner discussions, and I’m just putting that out to her and seeing how she communicates about these things and really what the truth is. So anyway, this is a super fun episode. It is a great bite-sized chunk episode. We just clip from one subject to the next subject to the next subject. It’ll definitely hold your attention. You’re definitely going to pick up some pearls along the way. Kristin is amazing, was so glad to have her. Guys, this episode is brought to you by Ceva Animal Health. 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. Kristin McDonald. How are you?
Dr. Kristin MacDonald:
I’m great. How are you, Andy?
Dr. Andy Roark:
I am so great. I am so glad that you are here. I have been looking forward to getting to sit down and talk with you a bit. For those who do not know you, you are a clinical cardiologist at VCA Animal Care Center in Sonoma, California. You are a huge outdoorsman, which I love, and you live in a beautiful place for it. You are also have two daughters just like I do, and you are teaching one of them to drive just like I am. I feel like we’re living parallel lives except for the whole cardiology thing. You are also a lecturer. You are doing VCA lecture series all across the United States. People can find you all over the place in your presentations. So yeah, thank you. Thank you so much for making time to be here. I’ve got a fun game and it is, I wanted to share with you some cardiology myths. I want to make some bold statements and I want you to shoot ’em down. So yeah, I want to go ahead and lay out some things that I am starting to hear or things that have kind of floated around the internet and I just want you to weigh in on some of the modern cardiology legends. Is that okay?
Dr. Kristin MacDonald:
That sounds great.
Dr. Andy Roark:
Alright, great. So first thing I’m going to start with is talk to me a bit about pet owners that are concerned about their dog having a heart attack. And so I see a lot in people. I’ve heard people say that dogs don’t have heart attacks. They’re like, dogs have heart attacks. I’m like, well, they do. And then people talk about heart failure and they’ll use heart attack interchangeably. Like, oh, well the doctor says he’s going to have a heart attack, and I’m like, nobody did that. Talk to me a bit about heart attacks in dogs and that terminology, if you don’t mind.
Dr. Kristin MacDonald:
Well, most clients actually equate heart disease in dogs to what they might suffer in human cardiology, which is a heart attack and it really is not the same thing. So dogs have a lot of different heart diseases, some that are in common with people, but they don’t have coronary artery disease and atherosclerosis. And I’m guessing it’s because we probably feed them better than we eat ourselves. Looking at my diet lately of lots of pastries and french fries on vacation, my dog eating way better than me. So there are certain things that may look like a heart attack that they may clinging to in severe forms. Their pet might be short of breath or breathing hard or coughing or collapsing. And so those things look like a heart attack, but it’s actually a very different process to a severe process. So we try to explain the actual heart disease that we think is going on with their pets so they can better understand it.
Dr. Andy Roark:
A couple of years ago, the grain-free heart disease was everywhere. It was huge thing. It blew up. There was much conversation about grain-free diets and their interaction with heart disease and things like that. That seems to have quieted way down. We don’t hear a whole lot about grain-free diet associated dilated cardiomyopathy anymore. Is that over? Is grain-free diet, heart disease a thing of the past?
Dr. Kristin MacDonald:
It is not over. It’s just not front and center on people’s minds. And unfortunately there are still cases of this. This was first described back in 2018 when we started seeing dogs that weren’t supposed to have dilated cardiomyopathy like little dogs that never get that disease. And we were looking at common threads and sure enough it was these grain-free diets that seemed to be emerging as this common factor. So there was this frenzy of learning and reporting to the FDA, which was a very arduous process for clients. It could take 30 minutes for them to have to fill out all this information and there gets to be fatigue in the process and fatigue with investigators. So there’s still ongoing active research, but I think that maybe the word has gotten out and maybe there’s been some reformulation of different diets, but there’s also very sneaky ways that companies are sorting the term grain free. And so they may call it grain friendly, but they still may have the same potentially toxic ingredients. We’re learning that it’s the legume family like peas and so they might call it green friendly where it’s more approachable. They still kept the peas in it. So we still are finding dogs with this and they can die from it. Changing the diet and treating for heart disease in these dogs can make a dramatic improvement in their outcomes. So it’s still around.
Dr. Andy Roark:
I can’t fathom. I’ve seen grain friendly and I’m like, oh, clearly they have addressed the concerns. But you say, but not necessarily.
Dr. Kristin MacDonald:
You have to look at now. It’s harder. You can’t just look at the title of the diet. You actually have to look at the ingredients list. It’s very complicated.
Dr. Andy Roark:
Oh man, I’m going to have to sit with that. That’s amazing. Talk to me about having seizures with heart problems. So I’ve had pet owners, I’ve seen posts on the internet where pet owners are like, yeah, my dog have heart disease and now he has seizures. How do you talk to people about seizures when their dog has heart disease?
Dr. Kristin MacDonald:
This is something or
Dr. Andy Roark:
Perception of seizures. Yeah.
Dr. Kristin MacDonald:
Oh, yes. This is something. Now full disclosure, I’m married to a veterinary neurologist, so this is a sensitive subject here. And we also happen to work in the same practice. So we’re often jockeying for whose case is this?
Dr. Andy Roark:
Well, hold on to jump in. Your father is also a veterinary dermatologist. Is that true’s like Oh, Thanksgiving’s at your house? Yeah.
Dr. Kristin MacDonald:
There was one actual Ettinger textbook that the three of us all had chapters in it and the table of contents had us in sequential order.
Dr. Andy Roark:
That’s got to be a record. That has to be a record. That’s super cool. Okay, I’m sorry. I didn’t mean to interrupt.
Dr. Kristin MacDonald:
So back to every time an animal has something where it looks like they collapse, they may lose consciousness, they may have some tonic CLO movement. They almost always call it a seizure, and it’s very difficult even in the best trained eyes and education to differentiate them. I’ve actually seen a dog in the ICU with an EKG on that went into horrible vtac, collapsed and fainted, and then had myoclonic movements that looked exactly like a seizure. But I had the EKG on and he had minimal blood flow and it was syncope. So of course an untrained client would think it’s seizure, but you’ve got to think twice about that and it’s hard for the GP because they’ve got to decide completely different directions to go, is this a really malignant cardiac event, cardiac or is this neurologic? Who do I send this to or what treatment should I start?
So it can be tricky because they can have similar appearances, but there’s a few things that I’m going to look for. I’m going to look at is there an inciting cause for syncope? It might be that it’s excitable or exertion related or triggered by a cough, or maybe it’s a small breed dog with chronic respiratory clinical signs in murmurs where for seizure it may be more likely at night when they’re resting and they may have different behaviors before and after, but it can be super tricky. But generally when a client says it’s a seizure, I would urge you guys to dig in deeper, get a little more info, look at your patient signalman and decide which direction should we go. And if there’s any questions, I’d be dialing up your favorite cardiologist or neurologist and tell them about it. Ask for a video.
Dr. Andy Roark:
Yeah. Well, I love the video suggestion, and this is always interesting because it really is the clinical history and asking the questions and kind of digging in. Do you still put halter monitors on dogs that you are playing around with syncope? Is that still a standard of care that you reach
Dr. Kristin MacDonald:
For? Oh yes. So for sure the first thing we’re going to start with is in my cardiology practice is we’re going to do a really comprehensive echocardiogram. We’re going to look for pulmonary hypertension, especially in small breed dogs, really common cause of syncope we’re going to have an EKG on, but you never luck into that aha moment. That’s when we really lean on the Holter monitor where we may place it for a day or even up to seven days to try to document arrhythmia and maybe we can catch the event and actually show whether it is from an arrhythmia or not, and then that will implicate your treatment because we have many great drugs out there, anti-arrhythmic meds, or even pacemakers we’ll use in dogs to really cure the problem.
Dr. Andy Roark:
Yeah, there’s a lot of conversation when I look online and I look at pet owners that are talking about their pets with heart disease and things like that. There’s a lot of fear. So one of the questions I’ve honestly seen online is people say, my dog has a heart murmur. Does that mean he’s going to die? Again, I think I bring this up because I think all of us in vet practice, we see heart murmurs all the time and we know that, but I think sometimes we take it for granted that the pet owners, they’re going to understand when we don’t act like it’s a big deal, so they’re going to understand it’s not a big deal. But I don’t think that’s necessarily true. How do you talk to pet owners about heart disease, about their heart murmur, which can hit them like a hammer when they go, what do you mean my little dog has a heart? What do you mean her heart has a valve that’s not working the way it should? What is that conversation like with you?
Dr. Kristin MacDonald:
Well, actually you catch it first, so I feel for you very much because you’re the revealer. And then I have clients that come in and they’re on the ledge. They are holding their breath, they are wringing their hands. You can see every bit of body language is fear. The dog’s not afraid, the cat’s not afraid as much, but the client’s terrified. So I love it when I can come back into the room after we’ve done our workup literally 25 minutes later and say, one of my first things is we’re okay here. And so it’s really disgusting that a murmur doesn’t mean your dog is going to die. And in fact, the odds are greatly in your dogs or your cat’s favor that they’re going to be okay. But this can get worse over time. And if we’re talking about the number one cause of murmurs in dogs, it’s going to be mitral valve disease, which yes, this can get worse over years of life, but again, if you’re a betting person, two thirds of dogs are going to live full lives with mitral valve disease. So it’s kind of giving them a little bit of reassurance and also committing them to the fact that things can go wrong and we need to stay on top of this. And that means we need to proactively prospectively watch these dogs and really monitor them to know when do we need to get worried and when do we need to start medications because certainly heart disease is not always benign and it can really progress to become problematic.
Dr. Andy Roark:
How do you handle the pet owners who, I mean again, so we talked about heart murmurs. When we start talking about heart failure, I have had clients come up to me or people who aren’t my clients, they talk to another vet and it’s almost like they have a question they’re embarrassed to ask their vet. So they say heart failure, that means he’s going to die, right? Heart failure is you can’t live if your heart fails and he’s in heart failure, does that mean he’s dying? And so unpack that for me.
Dr. Kristin MacDonald:
I literally had that happen to me last week. I kid you not right before this podcast. I was like, oh, this is it. This is definitely a myth that we need to dispel that heart failure is concerning. It’s a scary word because oh, it’s terrifying. This is a big deal. I mean, this is not a benign process typically, but it doesn’t mean your dog is dying on the floor in front of us. It means that your dog has severe heart disease severe enough that it cannot function properly, such that fluid will build up in the lungs or in the abdomen, or maybe they have really low blood flow so that they’re really tired going on walks or they’re coughing and breathing hard in that yes, heart failure, there are medications do help it just in people and think they may relate to that. They know like, oh, I have a lot of clients that go, well, I have heart failure.
I’m on that med. And so it almost makes them a little more comfortable to know we can treat this. But yes, overall there is a accelerated time course compared to people that can live with heart failure for 10 years, 20 years in dogs. I mean, it’s sad about most dogs with mitral valve disease and heart failure may live on average a year. Then again, we have some great success stories for longer and for dilated neuropathy, it’s even shorter. So there is this, in my approach, it’s an honest, gentle preparation for them so that we’re not sugarcoating things. We’re not trying to diverge from the truth, but we’re trying to support them, trying support and let them know what might happen, what it might look like. They always want to know what’s it going to look like, what’s the end going to look like? And I think it’s really helpful to discuss what it could be like with breathing difficulty that maybe it’s a phone call, kind of things are getting worse or maybe it’s a crisis and you need to get help urgently.
Dr. Andy Roark:
Do you think that you can have those honest conversations about what heart failure looks like and then still have sort of a voice of optimism?
Dr. Kristin MacDonald:
Yeah, absolutely. I think that I try to talk about that this is treatable and kind of a plan for what this looks like, but then we do have to talk about when things don’t go right. But also the fact that even if we have a dog that represents with heart failure, it doesn’t mean that we can’t make more adjustments and get more quality time. And I also think it helps with buy-in for medications because in veterinary medicine we don’t have so much success or there’s not as much availability of valve replacement. So really the mainstay of treatment cross country is medical therapy. And so if they know this is a deadly disease and we worry most about how they feel that medications are going to help deliver that improvement as best as we can, and we need them to be compliant and follow up and know what to look for that are concerns to let us know so we can be proactive.
Dr. Andy Roark:
Okay. Well, speaking of medical therapy, one of the things that I have seen in the last 16 months I have never seen since I was in vet school and learned about spironolactone, I have not put much thought into spironolactone until about 16 months ago when I started to really hear an uptick about conversations about Spironolactone. And so the debate that I’ve seen online, which is actually again, this isn’t pet owner for, but it’s interesting, but people are like, if you’ve got Lasix that’s so much stronger, you don’t need spironolactone if you got Lasix. And so let me put that to you as a potential myth that’s out there. How do you feel about that?
Dr. Kristin MacDonald:
I too was educated that it’s a weak diuretic. And really at that time until about a year and a half ago, I’ve been waiting for the data. I like data. I think it’s reassuring. It helps me to know is this worth it or not? And so we’re looking at effects within oftentimes like mitral valve disease and heart failure. And really we’re thinking about spironolactone is not a diuretic. We’re thinking about it kind of like an ACE inhibitor where it’s more of a renin, angiotensin, aldosterone system blocker. So it’s blocking aldosterone receptors. And so we think of it more in that neurohormonal antagonism rather than its effect on increasing urinary output. And there are definitely benefits that have been shown when you add spironolactone to benazepril that these dogs, they had a lot longer time before heart failure worsened and they lived longer and they had less time to what they call at all cause removal or all cause problems. So it’s very safe and effective and we’re learning that it’s not all about just how much urination they’re going to have in diuresis to have an actual benefit. But again, it’s not a one or the other. The beautiful part is that we can use multiple medications at each, have their own job to cumulatively get the benefit.
Dr. Andy Roark:
Well, tell me more about that. Talk to me a bit about quad therapy. So I’m hearing the term quad therapy in our cardiac cases and things. Can you define that for me, is what that means to you and then start to make the case for a quad therapy approach?
Dr. Kristin MacDonald:
Yeah, when I think we all talked about triple therapy, when PMO Bendin became available, we had of course our standard puric amide loop diuretic pulls the fluid from the lungs. We’ve got ACE inhibitors which are blocking the conversion of angiotensin one to two. And earlier studies showed improvement in heart failure class and double survival time. So that was back in the eighties to nineties. Then came pob Bendin, this revolutionary drug that has honestly changed the face of cardiology. It’s made us have a lot more fun and a lot better outcomes.
Dr. Andy Roark:
It should be in the water,
Dr. Kristin MacDonald:
A lot of happy, happy dogs and clients with this drug being an inod dilator. So what we’re looking at is I describe it to owners as this is the one that helps the heart function better and dilates vessels both going out the body and back to the lungs. So this really helps heart failure, many causes. And of course that one demonstrated again, improvement in survival, time and time to heart failure, recurrence, all of that is really something we’re looking for. So now comes on the scene spironolactone, and we just had this best clinical trial that I kind of honestly was waiting for. And what that is looking at is blocking aldosterone receptors with spironolactone and what aldosterone, it’s a toxic neuro hormone. And unfortunately when dogs or cats are placed on ACE inhibitors, we want to believe that there will be less angiotensin too made, which then lessens production of aldosterone. Well, that’s logical, but the body has different workarounds. And so about 40 to 50% of animals people, they have this aldosterone breakthrough where we still have elevated toxic aldosterone circulating in the body that’s wreaking havoc on the cardiovascular system. So we’re looking at now blocking both the ACE system and aldosterone, and I think of it as kind of like peanut butter and jelly, or actually it’d be more like chocolate and peanut butter. For me, the perfect combination really for more comprehensive blockade.
Dr. Andy Roark:
Is it hard to get clients to buy into quad therapy? I mean, we’re talking about giving a number of different medications. If some were to make the case and they were like, it’s better to do fewer things the client will actually do. How do you feel about that?
Dr. Kristin MacDonald:
Very
Dr. Andy Roark:
Tricky. Shoot that down for me if you can.
Dr. Kristin MacDonald:
It’s a tricky, tricky thing. And unfortunately a lot of these dogs are coming to me and have never even seen POB bendin yet. And so they may be on no medications and they come in for a little cough, they think they’ve got kemal cough, things are great, and then I’m telling them their dog is congestive heart failure and may live for a year. This is a lot to handle. So then we start talking about quad therapy, four different drugs. And some clients will get worried like, well, is it safe? Is it toxic drugs might be toxic? Well, yes, we do have to follow kidney values and all, but they are very safe. But then comes the reality of implementation. So how compliant might a client be able to be with four different medications given often twice a day? And unfortunately, doctors, they want to believe they have the perfect pupils that will do everything perfectly.
But I think we may be perfect cases that humans are going to mess up and they’re going to be busy and going to a lot of other stuff on their plate looking at a lot of clients say they cannot handle giving more than three meds. They say, I can’t even do two meds a day. And about 30% said they could give at most three meds a day and that they couldn’t handle more. So I often look at, there’s a nice combination tablet where we have both the NPR and Spironolactone and one tablet given once a day. And so I don’t sneak it in. I just say, well, we’ve got three medications your pet’s going to go home on little. And I sort of say, by the way, one of them happens to have a two in one, so it makes it a little easier for them to handle.
And it’s even easier if they’ve already come in on PMO bendin for preclinical, say, heart enlargement. And then I say, well, we’re just going to add two more medications that are going to help the heart failure part of things. But it’s very tricky. The other part is will the pet take the medication? Maybe the client is absolutely on board. They are dependable. They know they’ve been educated to say, this is how your dog is going to have a good life and live longer, but we have to give the med or it’s not going to work well talking pet language. Your dog or cat may not agree with that, so we’ve got to make sure they know how to give the med. Maybe they may need reminders or training on that. So there’s some great apps out there. I mean there’s apps for everything these days. But I do love the Cardis app because it helps them monitor breathing rights and it has medication reminders and you can have multiple pets. And I do have families that have three animals and heart failure all at once. So just giving them the tools to help them with the delivery.
Dr. Andy Roark:
I love it. Dr. Krista McDonald, thank you so much for being here. You are so wonderful. Where can people learn more from you? Where can they find you online or in the future?
Dr. Kristin MacDonald:
I might be a bit of a dinosaur, but I have a LinkedIn. I don’t check it that much, but really VCA Animal Care Center of Sonoma and LinkedIn. But overall, I also go incognito because online I have a Facebook that’s my own personal Facebook with last namely. Oh, okay. Yeah. But probably through VCA. I am actually going to have a really fun time weekend before school starts. My daughters and I are going to go to Vet Girl U down in Scottsdale at the Princess, and we’re going to have a great time with my mom-in-Law. Oh man. Yeah, you guys should check it out.
Dr. Andy Roark:
Yes, vet Girl u Justine Lee and Garrett Pater are good friends of mine’s founder of Night Girl. Just wonderful people. They’ve got a great event. They have a great culture. I think the world of them. That’s fantastic. Yeah. Awesome. Thank you. Thank you guys. Take care of yourselves, everybody. I’ll talk to you soon. Thank you. And that’s it. That’s what I got for you guys. I hope you enjoyed it. I hope you got something out of it. Real quick before you go, I got to give you a fast heads up. I have a Ray CE webinar coming right at you very soon. It is called The Practical Guide to the Mitral Valve Patient. This is with my friend Dr. Natalie Marks. It is on November 29th at 4:00 PM Eastern. That’s 1:00 PM Pacific. It’s sponsored by Ceva Animal Health. Guys. I’ve worked with Natalie many times. She’s been on this podcast many times. She’s absolutely great, super practical, a really wonderful doctor to learn from. This is going to be packed full of pearls, like I said, free hour race, ce. Jump in and grab it. Link is in the show notes. Get on it fast because this is going to pass us by real quick. Anyway, coming at you. I’d love to see you there, and that’s what I got for you today. Take care of yourselves, everybody. See you later.
