Dr. Anna McManamey, Professor of Cardiology at Purdue’s College of Veterinary Medicine, joins Dr. Andy Roark to discuss a common yet challenging case: a new heart murmur in a cat scheduled for a dental procedure. In this Hall of Fame episode, Dr. Mack unpacks the potential causes of heart murmurs in cats, with a focus on hypertrophic cardiomyopathy (HCM) and other conditions that could impact anesthesia safety and long-term health. She highlights the diagnostic tools available, including the limitations of chest x-rays, the value of BNP testing as a “poor man’s echocardiogram,” and when to consider additional tests like blood pressure or thyroid screening.
Dr. Mack also provides practical advice on managing heart disease in cats, emphasizing the importance of preventive measures like blood thinners and the challenges of owner compliance with medications. For emergency settings, she shares tips on using SNAP BNP tests for quick assessments. Throughout the conversation, Dr. Mack’s expertise shines as she equips veterinary professionals with actionable insights to confidently address feline cardiology cases. Let’s get into this episode!
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ABOUT OUR GUEST
Dr. McManamey (aka Dr. Mac) is a veterinary cardiologist. She received her degree of veterinary medicine from the University of Missouri. She then completed a rotating internship at the Ohio State University followed by an emergency and critical care internship at North Carolina State University. She finished her cardiology residency at North Carolina State University and became an ACVIM diplomate in 2021. Dr. Mac is currently an assistant clinical professor at Purdue University in Indiana. Cardiology is her favorite subject because it can be made as simple or as complex as needed. Furthermore, every animal has a heart and that means Dr. Mac gets to work with all kinds of species. Her areas of interest within cardiology are echocardiogram, congenital heart disease and interventional procedures, as well as emergency management of cardiac disease. She has a very supportive and patient husband along with three canine fur-children, one of which had a patent ductus arteriosus (of course).
EPISODE TRANSCRIPT
Dr. Andy Roark: Welcome everybody to the Cone of Shame Veterinary Podcast. I am your host, Dr. Andy Roark guys. I got a great episode that we were pulling out of the vault. This is a hall of fame episode. That means it is one of our Top 10 Most Popular Podcast Episodes that we’ve ever had.
That means a lot on this show and so guys, this is a great one with Dr. Anna McManamey or Dr. Mac as she is called. We are talking about a four year old male neutered, domestic short hair who has a systolic heart murmur. And who’s scheduled for a dental. How worried about this? Should we be, do we blow it off and just do the dental?
Is this a reschedule thing? Do we need to refer this away? What do we say to the owners about the risks? Guys, you’re wondering, I see these cases and I stop and go. Oh, Am I about to make a good choice? That’s why this episode is a Hall of Famer. It’s great. Let’s get into it.
Kelsey Beth Carpenter: 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. Welcome back to the podcast. Doctor Mac, thanks for being here.
Dr. Anna McManamey: Thank you for having me.
Dr. Andy Roark: Oh man, I enjoy having you on the podcast. I’m so glad. I’m so glad you’re back. I have well, let me pause and introduce you to those who don’t, who don’t know. You are a professor of cardiology at Purdue’s College of Veterinary Medicine and a lecturer and a genuinely wonderful, smart person and a great darn teacher.
And so that’s why I hope that you would be able to help me out with this case.
Dr. Anna McManamey: Happy to be here. I sound so fancy when you say it that way.
Dr. Andy Roark: I know. I, I, yeah, I get introduced and people are like, this is Andy and he has this big title and I’m like, that sounds really fancy.
Dr. Anna McManamey: Yeah, obvious. I’m
Dr. Andy Roark: know, I’m like, boy, I hope they don’t ask me hard questions, because I can’t justify
Dr. Anna McManamey: a newbie cardiologist, but I’m enthusiastic. So
Dr. Andy Roark: No, you’re, I think, I think you’re amazing. I love having you on the podcast.
I have a kitty cat that I need help with. I, and again, maybe this is just my personal bias. Maybe it’s just the ratio of dogs to cats that we tend to see in practice. Maybe it’s just sort of the secretive nature of cats. Maybe it’s that cats are a little bit harder to deal with, to physically examine than dogs.
Sometimes I don’t feel like I find a lot of heart murmurs in cats relative to heart murmurs in dogs. But I got one. I have a four year old male neutered domestic short hair named Alabaster, who came in for a dental cleaning. And he’s got a heart murmur. He’s got a grade 2, maybe a grade 3. I’m not the best at nailing exactly easing the grade 2, 3 range.
Yeah, just a systolic heart murmur. No complaints from the owners. He’s, he’s not, He doesn’t seem to be coughing or anything. They said, I asked him, is he coughing? And they’re like, not more than usual. And so that usual, like, okay. Yeah, so it’s that. Yeah, so I’m looking at this, at this cat.
One is anesthesia patient, but then also number two is just a general maintenance, maintenance of a fairly young cat that I had not heard a heart murmur in before. Dr. Mack, how do you treat that? Where do you go with this
Dr. Anna McManamey: Yeah, I think it’s a great question. This is a very common scenario of why a lot of cats come to see me. Honestly. I think you, you hit a lot of good points right off the bat. Cats are sneaky cats. They hide their disease. They don’t usually act sick even when they are sick. And then there’s a very frustrating I guess, ratio of the number of cats that have heart murmurs that actually have heart disease.
And vice versa. So when you hear a murmur in a cat, I’d say it’s a 50-50 chance that they have structural heart disease. So still a reasonable chance that they do have that structural heart disease that you need to further investigate before putting them under anesthesia where they’re going to get fluids as, as part of their anesthetic protocol.
So in cats, a murmur usually is from some type of outflow tract obstruction. So whether that’s like an HOCM, so hypertrophic obstructive cardiomyopathy, or some type of less pathologic form, a dynamic right ventricular outflow tract obstruction. But usually that’s where we see these murmurs in these younger cats.
Mitral valve disease really isn’t common in cats. It happens in really older cats, like geriatric kind of cats, but in this young of an animal, I think it’s very appropriate. It’s a male cat. It’s a middle aged cat, domestic short hair. Those are animals that are predisposed to HCM and structural heart disease.
So what are you going to do with it? Well, I think If this were a dog, the answer would be easy. Take a set of baseline chest x rays, know what you’re dealing with. Unfortunately in cats, because their heart disease they get most commonly is a hypertrophic cardiomyopathy, it’s a concentric thickening of the ventricle.
So the ventricle thickens inward. And so taking x rays on a cat, their heart can look Miraculously normal, even if they have significant disease. So, I say that an x ray is helpful for ruling out severe, severe heart disease. Maybe, but honestly, if you see a big heart, they probably have heart disease. If you see a normal looking heart, they still could have heart disease.
Dr. Andy Roark: like, like 50 50 chance they could
Dr. Anna McManamey: like it’s, yeah, it’s frustrating, right? Because you’ve got this cat, you want to do the dental, it’s asymptomatic.
Dr. Andy Roark: Much less helpful, I know.
Dr. Anna McManamey: So, I still think x rays are okay. I think that again, if you see a big heart on x rays, then I’d say, well, you probably do have heart disease. If I see a normal heart on x rays, it just doesn’t rule out heart disease.
So x rays not wrong to do. The other thing that’s growing in popularity that I actually really like is something called the BNP. So this is the B type natriuretic peptide. So this is a biomarker. It is very, very specific for the heart. And what it tells us is if the heart is stretched. So it doesn’t tell us what the heart disease is.
It doesn’t matter if it’s even primary heart disease, it could be like in an older cat could be hyperthyroid heart disease, could be hypertensive heart disease. But what it tells us is that the ventricles are under some type of duress. They’re either having a pressure overload or a volume overload.
Something’s going on, and this is a blood test. It’s usually always gonna be sent out like Idex is the one that owns this test currently. So it’s gonna be a turnaround, so it’s not gonna be same day results. But it’s a simple blood test. You can do it with their pre anesthetic. blood work, for example it goes out.
The range for cats is pretty tight. It’s about 0 to 100 kind of picamole per liter is the, per deciliter is the range. And usually if it’s in that range, I don’t, I don’t worry at all about any type of structural heart disease. If it’s outside that range, it’s a pretty sensitive test. So you might get cats that have false positives, meaning it’s a little bit outside the range, but their hearts look very normal echocardiographically.
But that’s a good screening test. In my opinion, it’s better than maybe even x rays just because again, you can have pretty severe heart disease. but a normal heart on x rays. So the BMP, in my opinion, is the cheap man’s echo. Like it’s, you know, and if you can’t get to a cardiologist right away or you don’t have the money to get to a cardiologist, then a BMP is a very appropriate screening tool.
And I’m looking for that number to be higher than a hundred.
Dr. Andy Roark: Do you add that in as, as like a routine screening test for patients you’re planning to put under anesthesia? Is it, is it that level of screening tool utility or are you still thinking mostly, I have questions or concerns about, I add this onto. I’m just curious, like how are you, are you, are you just sending these out all day long or is this
Dr. Anna McManamey: this is a slippery slope. I’d say there’s, I’m definitely, I’m definitely in the
Dr. Andy Roark: and you’re a cardiologist too, you’re like, I’m not, you’re asking the wrong guy.
Dr. Anna McManamey: but I do, I think, like, I realize that not everyone can come see me, right? Like, I mean, we see, we see, you know, we’re in, it’s going to sound really bad when I tell you how many cases I see a day.
It’s not enough, but I don’t have enough time to see all these, all these cats. And so what are we going to do in the meantime? But I do think that the BNP in the cat. not so much the dog in the cat. I think it’s appropriate to start screening cats just like you do for hyperthyroidism.
Like there’s enough cats that don’t have heart murmurs, that have heart disease. And so wouldn’t it be nice if we could catch them earlier to just let the client know. What’s going on with their pet? What they need to watch out for with their pet? Is there any medication their pet should be on before congestive heart failure or something happens?
So I, I might make some people mad when I say that, but I do, I think it’s, I think it’s a good enough test that it, Might be worth doing more often.
Dr. Andy Roark: I mean, at what age do you start to think about screening for things like this, right? Because it is a, it is a measurement of sort of the state of the heart. So it seems like screening kittens is probably not gonna be super productive or really insightful for the future. But I mean, are you talking about five year old cats?
Are you talking about eight year olds? Is this a senior wellness type of screen in your mind? I’m just curious, kind of, kind of when you look in your crystal ball, kind of where do you see that going or how do you use that tool in your
Dr. Anna McManamey: Yeah. First of all, I highly recommend a crystal ball to every veterinarian because they do come in very, very handy.
Dr. Andy Roark: Well, I’ve, mine has been craptastic for the last three, four years. It’s just, boy,
Dr. Anna McManamey: wish I had one of those. But, but yeah, I, I think that’s a great question. So I would say if you look at HCM, hypertrophic cardiomyopathy, as a model of heart disease, because it’s the most common heart disease we see in cats, it’s usually around five to eight years of age where that kind of takes its, its peak, peak effect in cats.
However, we see some cats as young as three. So I think five, Seems like a magic number for me. I think maybe three is a little early, but you could catch some that are starting to show signs earlier, but I’d say as early as five, but I think kind of that eight years of age when you’re starting to screen for hyperthyroidism, it’s probably appropriate to be doing the same for, for the heart.
Dr. Andy Roark: talk to me, talk to me a little bit about blood pressure in these cats. Is, is that going to be an insightful tool when I, you know, I’ve got this, this sort of heart murmur? Yeah. I mean, is that something, I, it didn’t come, it didn’t come immediately to hand, I guess, when we talked about chest x rays and we talked about the BMP is, is there, is there a real value in trying to get this cat calmed down in a nice. Secluded place and try to get a good blood pressure and, and, and what can I, what can I gain
Dr. Anna McManamey: Yeah. That’s a great question. So I usually will reserve the blood pressure. I think it’s a very important test, but I usually will keep it for a little bit later in the lifespan of the cat. So it’s unlikely that the cat at this age, at five years of age is going to have systemic hypertension. However, that’s a very cheap, very accessible test to do because again, if your BNP is high, it’s You’re kind of obligated to check a systemic blood pressure and to check a thyroid level again, even though it’s unlikely in a cat that young, if those 2 diseases are present, whether that systemic hypertension or hyperthyroidism, both of those conditions cause a thick left ventricle would cause an elevated BMP.
So definitely has its place again in that age range. I’d be less suspicious of it, but totally appropriate to do.
Dr. Andy Roark: Let’s talk about management of heart disease in cats. And I, I think that’s something that probably compliance and adherence are, are often a bit of a challenge. It’s hard, especially if we have ongoing medications for, for these cats. How do you introduce the idea of, you know of long term medication to pet owners? What, what sort of pearls of advice do you have for, for setting, setting pet owners for?
Dr. Anna McManamey: Yeah, it’s a great question. And I think with cats, it’s just a whole nother level of difficulty than compared to dogs. You’ll get the occasional cat that just eats everything you put in front of them, but that’s not always going to be the case. So the good news is that cats with heart disease. Again, HCM being the most common, really the only medication that we routinely recommend in these guys before congestive heart failure happens is a blood thinner.
And Plavix, Copitagrel, we do think it’s probably better than just aspirin for, for preventing that thromboembolic event. That’s kind of, that’s that big scary thing that we really want to be able to just let clients know their cat has a risk for it. I would say a lot of ATEs, aortic thromboembolism that I see, unfortunately, it’s the first time the owner ever knew their cat had disease.
So that’s the one that we’re trying to protect them with. And so really the left atrium has to be big for them to be at that risk. In most cases, I’ll say like less than, less than 5 percent of cats that have ATEs have a normal left atrium size. So most of the time the left atrium is big. If they have a high BNP, if I would say probably at least over 200 BNP range, if we echo them and they have a big left atrium, blood thinner is what we’re prioritizing in terms of treatment.
It’s a once a day therapy. It’s a small pill. So those things are in our favor. Once heart failure happens, congestive failure happens, then it’s really, it’s furosemide and their Plavix plus or minus an ACE inhibitor. We don’t have that same evidence that it has to have that ACE inhibitor. to have a better prognosis once congestive heart failure happens like we do in dogs.
Does it make sense that they would do better? Yeah, it makes sense, but we don’t have that exact evidence. So if congestive heart failure happens and I have a cat that the client can’t medicate well I’m just going to prioritize what I need to give them. And that’s their LASIK, which is a small pill.
And That’s their plavix or some type of blood thinner to try to reduce that risk of an A. T. E. I have cats that are on injectable drugs. They’re on injectable lasix because they can’t owner can’t medicate them. So it’s kind of like a diabetic cat in that stance. So we’re just giving injections of lasix twice a day instead of giving oral medications.
You know, you can coat the meds in some butter, you can coat them in cottage cheese, you know, those kinds of tricks. But unfortunately, at least not yet, are like transdermal medications. I think that would be a godsend if we could get some bioavailable transdermal Plavix or transdermal Lasix, something like that for these kind of cats.
Dr. Andy Roark: no success in that regard
Dr. Anna McManamey: Not yet, not
Dr. Andy Roark: I’ve heard people mention Pimobendin in cats, is that, is, yeah,
Dr. Anna McManamey: yeah,
Dr. Andy Roark: Yeah, I, that, that’s kind of one of those back alley
Dr. Anna McManamey: it’s, it’s the, I, I was listening to one of your podcasts with Dr journey and she was like, there is the religion debate, right? So, yeah, yeah. So I would say that for, for the asymptomatic cat. So the cat that’s not in congestive heart failure, there’s, there’s probably no cardiologist that’s going to recommend Pimobendan in those cats.
So different than dogs. If there is a cat with congestive heart failure, some cardiologists might start Pimobendin in those cats. The rule for me is if there is a murmur, don’t give the Pimobendin because Pimobendin worsens dynamic obstruction. So if you already have a heart murmur, odds are it’s dynamic obstruction.
Giving Pimobendin will worsen that obstruction. So that’s kind of my general rule. If there’s a murmur, And heart failure in the cat, just don’t give PEMO, just stick with your Lasix, your Plavix, plus or minus your ACE inhibitor.
Dr. Andy Roark: that’s super useful. Thank you, thank you for walking through this with me. Are there any final pearls, words of wisdom, or pitfalls I should look out for, just in general dealing with heart disease in a cat?
Dr. Anna McManamey: Yeah, I think something that you actually mentioned in part of the history was coughing in cats. Coughing in the cat rarely is from heart disease, rarely is from congestive heart failure. I’d say the only times they see cats coughing with congestive heart failure is if they have a significant amount of cough.
Plural effusion or a significant amount of pericardial effusion, which are both presentations of left sided congestive heart failure in the cat. So the coughing cat with the murmur to me, I actually move heart failure way down on my list and prioritize other things. The other little tidbit I’ll leave you with is if you’re in the ER setting and you tap a cat’s chest, do a thoracocentesis, and you just want to know, is this heart failure or not?
You can run that sample on a BNP test. So you don’t even have to use the blood. And there’s, there’s these BNP tests, the B type natriuretic peptide tests that are SNAP tests that are available for the ER setting. It just tells you, is it normal? Is it abnormal? That’s a same day test. It’s SNAP. It’s eight minutes.
But you can run that on blood, serum, or the, the pleural effusion. And you actually get a pretty good result with that.
Dr. Andy Roark: That is super useful. Awesome. Thank you. Thank you. Thanks for thanks for sharing. I’ll tell you real quick. I, I remember being a first year veterinarian and I had a cat that had a chest full of fluid and I was going to tap it and the owner was there and I was getting ready to do it and he said, how many of these have you done before? And I was like, I wish you hadn’t asked me that and and then I was like, I’m gonna be honest and I’m like None, but I’ve read about them and he was like is there someone else who could do this and I had to go get I Didn’t I did I went most humbling
Dr. Anna McManamey: oh my
Dr. Andy Roark: but
Dr. Anna McManamey: that happens, that still happens to me, they’re like, how many have you done? And the, the, the devil on my shoulder wants to say, whether it’s one or a hundred, I’m all you got. So you’ll find
Dr. Andy Roark: Yeah, you exactly right. Yeah. And just for me, I worked at a big practice. There were like literally a dozen other vets and they were like, won’t you get somebody else junior? I’ll never. I’ve, that’s, that’s whenever I started to tap a cat’s chest. Cat’s chest. I think. How many of things I done, it’s like, oh, a dozen.
Okay. You know? But oh man, that’s funny. But yeah. Well. like you did a rotating internship, you did an emergency critical care internship and then you did a residency, there’s probably not a whole lot that you haven’t done once
Dr. Anna McManamey: least once. Yeah, but it, but it’s, it’s, it’s always a little humbling and you’re kind of like, how do I answer that?
Dr. Andy Roark: I, you know, I, I do, I’ve been doing vet medicine for 13 years and I am humble. Every, every day and I go in there and go, Oh, well, I love it. You know, we always, we always, I think, I think if it wasn’t that way, I think it might get boring. And it’s, you know, that medicine is a lot of things,
Dr. Anna McManamey: Never boring.
Dr. Andy Roark: Boring is not one of them.
Thank you, my friend. Thanks for being
Dr. Anna McManamey: My pleasure. Thank you.
Dr. Andy Roark: And that’s what I got, guys. I hope you enjoyed it is a hall of fame episode from Dr. Mac. Thanks for being here. Take care. Everybody, we’ll talk to you later.
