Episode Transcript
[00:00:02] Introduction: Welcome to All Cats Considered, a podcast from the Feline Veterinary Medical Association.
Here we interview professionals from across the veterinary world and take deep dives into the latest evidence based research developments, studies and guidelines that improve feline health and well being.
We are the home for veterinary professionals seeking to enhance the care of cats through high standards of practice, continuing education and evidence based medicine. In each episode you'll hear interviews with a variety of experts in our field covering a wide range of topics and the latest developments in feline health. We'll share the key points you need to know to improve your patients care.
Let's dive in and listen to this week's experts.
[00:00:45] Michelle Meyer: So I am Dr. Michelle Meyer. I'm a general practitioner, past president of the Feline Veterinary Medical association.
And I'm here speaking with Dr. Luca Ferasin, who's a boarded cardiologist practicing in England but used to teach at University of Minnesota.
[00:01:02] Luca Ferasin: That's correct.
[00:01:03] Michelle Meyer: And so as a general practitioner a lot of us hear heart murmurs in cats and we would like to know what would you recommend?
Usually I start with running a cardiac bnp. What age would you recommend we start doing that if you hear a heart murmur in a cat?
[00:01:17] Luca Ferasin: Well, it very depends when the murmur is first auscultated. Could be a congenital defect, so you can hear it in a very young kitten or could be an acquired condition so it appears later in life.
It's difficult because obviously, ideally, ideally we should do an echocardiogram in all these cases with a heart murmur to find out whether there are significant conditions, whether they are associated with a significant structural or, or a functional abnormality. But we also know that approximately 56% of cats have a murmur with a murmur do not have any structural or functional abnormality that we can see echocardiographically.
So in an ideal world we should, if there was financial availability for an echocardiogram, I would recommend it in all cats in order to find out whether that murmur is clinically relevant or not.
But I do appreciate that sometimes these echocardiographic exams can be quite expensive and if there is not the financial availability to undergo an echocardiogram, then we need to find different strategies so we know that the loudness of the murmur can be an indication. So if the murmur is very loud, usually it's associated with a significant condition and very often is a congenital abnormality that gives these very loud murmurs. Majority of murmurs in cats are soft and therefore it's a little bit more challenging. So running NT probnp is certainly a very clever idea because if the NT probnp is normal or near normal, then it's very unlikely to be associated that murmur to be associated with a significant cardiac condition. That of course doesn't mean that cardiac condition will not progress over time and therefore we probably need serial measurements of NT Probnp, but that's certainly a very good idea. So if the antibrium Probnp is normal, even with a simple SNAP test, then perhaps we can wait and reassess the case later on without necessarily rushing into echocardiographic examination.
But if the NT probnp is elevated, that, you know, it becomes a little bit more justifiable to to run an echocardiogram so we can find out whether it's associated with a significant underlying condition and then intervene accordingly.
[00:03:42] Michelle Meyer: I've often read that 1 in 7 cats isn't 13%. Maybe cats have cardiac disease. Do you find that to be true?
[00:03:51] Luca Ferasin: Well, it's difficult to answer this question for me because we are a little bit biased. We are obviously a referral institution so we see only referral cases for catiat conditions. It is true sometimes they turn up to be normal cats, but normally we see all cardia patients.
So I don't know exactly what the prevalence is because although I said earlier that 56% of murmurs in cancer not associated with the heart disease, it's also true that a lot of cardiac conditions, significant cardiac conditions, do not have a murmur. And that is obviously a completely different story. And so it's difficult to screen these patients because unless we do like for example an NT pro BNP test on an annual recheck for a vaccination and so on, is very difficult to detect these silent cardiac conditions.
This comes as a problem for us because unlike dogs, where we normally make a very early diagnosis, we follow them over time till the point they develop heart failure. In cast, the majority of cases they develop heart failure without any known cardiac condition. So now cardiac abnormalities reporting their history and this is a real challenge. So unfortunately we don't have a magic bullet for that. Probably screening with antiprobnp on an annual basis would be a very good idea but again it very depends on the financial availability of the client.
[00:05:19] Michelle Meyer: Sure. And then if I do get an NC broad pnp, I recommend they go and see the cardiologist and get an echo.
Where I live it's often a year out that he's booked and he does his best to get patients in their office. If we can't, is there anything you would recommend, medication wise, that you would do?
[00:05:36] Luca Ferasin: Start a count on well, that would be difficult. It's a very good question, but a difficult answer because it will be like stabbing in the dark. So what are we treating? If they're not symptomatic, so they don't have evidence of congestive heart failure, namely breathing difficulty, they then what do we treat? Besides we don't have any at the moment, any medication or any intervention that can slow down the progression of a disease. There are some promising data coming out, but obviously we need to wait for longitudinal studies. So perhaps in a year or two, if you ask me the same question in a couple of years, I may have a different answer. But at the moment it's very difficult to treat something we don't know. And therefore my approach, I tend to be quite conservative and even more conservative with age.
So I was a little bit more aggressive earlier in my career. So I would just refrain from intervening with any medication until we know what's going on.
[00:06:34] Michelle Meyer: So if we do have a cat in congestive heart failure, and I have a lot of patients who have a hard time giving oral meds, have you ever sent them home with injectable lasix to give?
[00:06:42] Luca Ferasin: Yeah, that's an excellent question because actually these this morning I presented some results of a study we presented at the European College of Agio Internal Medicine a few weeks ago.
And we reviewed our patients that at one point our cats, they were in congestive heart failure and then they stopped responding to furosemide or torazomide after a period of time. So in this case, when the cat parents were considered euthanasia, we proposed injectable furotanoid. Obviously not every single pet owner is prepared to give injections. A lot of people are, have got this needle phobia and they can't really physically or mentally approach this type of medication. But majority of them, I must say they're pretty good. We have our technicians that can train them how to inject pretty much the same way we do with cats with diabetes, for example, when they receive injectable insulin.
So that's certainly an option because by doing that we bypass the problem of the so called heart gut axis. So in other words, if we want a cardiac condition, whether it is causing right sided failure or left sided failure doesn't matter. We've got to reduce absorption at the level of the intestine, which is responsible, partially responsible for cases of cardiac cache we see in more advanced cases, but also for the resistance to and diuretics. So one of the causes of insulin resistance is the poor absorption. So by giving injection, we bypass the intestine and therefore we get a new response to diuretics that we were not seeing any longer in these patients. And in this study, we had 13 cats that responded to these characteristics. And as an average, they had an additional 90 days of good quality of life. Simply because we managed to alleviate the signs of congestive heart failure that were no longer possible. We couldn't possibly control with all the medication. And so I think it's a valuable intervention and something that has been advocated for many, many years. But we're now trying to make a little bit more objective with these studies.
[00:08:58] Michelle Meyer: Thank you.
What monitoring things would you recommend pet owners do at home to help make sure their cat is doing okay?
[00:09:05] Luca Ferasin: Well, if we have a well controlled congestive heart failure, the breathing rate would be the best way to monitor. It's completely inexpensive. It doesn't take much effort to do it because it takes 30 or 60 seconds every couple of days. So what we do, we train these pet owners to monitor the sleeping respiratory rate. My resting respiratory rate is okay, but it's a little bit less consistent, a little bit more elevated values compared to the sleepy respiratory rate. But we have proven with a previous study that a well controlled congestive heart failure, both in dogs and cats, will give a respiratory rate during sleep. So a sleep respiratory rate below 30 breaths per minute. We use this strategy with all our patients. Every cardiac patient that goes home on diuretis will have this instruction. And then there are some mobile apps that can be used and so these owners can send us the recordings on a monthly basis. We have every day. We got somebody in our team allocated to read all these graphs. Boring stuff, but extremely helpful because if we see the breeding rate remaining constant, we just reply by email. We say, create control.
Thank you for your data. Let's see the next result in a month. But if we do, if we see the breeding rate going up consistently progressively over time, then we pick up the phone image, we say, we might have a problem, let's see your cat again. Or let's try to increase the dose of furosemide and see how it goes. So we stay in touch over the phone in order to see whether we can adjust the response to diuretics.
Good.
[00:10:46] Michelle Meyer: Yeah. I often recommend respiratory rate when they're sleeping because sometimes when they're purring, they breathe faster and people.
[00:10:52] Luca Ferasin: Oh, absolutely. That would be certainly a confounding factor. But also smells, the vision of things moving in the house, sounds, et cetera, have got a much higher effect in an awake patient than in a cat asleep.
[00:11:08] Michelle Meyer: And is there any recommendations you would make on those? Very scared and typically they get very aggressive in the hospital because they're being defensive for sedation. That would be heart safe.
[00:11:22] Luca Ferasin: Yeah. Okay. So there are different possibilities here. Obviously very stressy cuts are difficult for a variety of reasons. So it's always recommended to preemptively give some gabapentin. For example, when it comes to the hospital, we normally recommend giving gabapentin the night before and a couple of hours before coming to our clinic if there is a known history of predisposed to stress.
Sometimes we still need to sedate with combination of drugs, but that is not very common. In the last survey we did, we found that only 4% of our cats were sedated for an echocardiographic examination. So majority of them will cooperate. If you implement the cat friendly strategies in your clinic, then the chances to be successful are much, much higher.
But it's also true that if we have a cat recongestive art failure where the stress can be a very deleterious factor, but then we try not to see them again. So we try to stay in touch with these owners over the phone in order to avoid any additional stress associated with the journey in the car to come and see us or the waiting in the waiting room. So even if you got all the cat friendly implementations in your clinic, probably it's a better idea not to stress them anymore. And sometimes just a phone call and advise to increase or reduce the dose of furosemide or any or the diuretic can be very helpful.
[00:12:53] Michelle Meyer: And I see a lot of kittens that often have a heart murmur and they seem to grow out of it. Was there an age that you would be worried if they still had a murmur at a certain age that we should have them go see if.
[00:13:06] Luca Ferasin: Well, that's a very good question. I think this is the approach of 99.9% of vets.
And these murmurs that are heard in young kittens and then they disappear later in life are called innocent murmurs or flow murmurs. Usually they're associated with an exuberant contraction of the myocardium due to excitement primarily. And that can give a sort of turbulence in the outflow tract. It is responsible of the murmur.
I follow a lot of human cardiologists in the past and I've seen how they approach these children with murmurs. So if the murmur is relatively soft, it changes with body position, changes with the heart rate. That's very likely to be one of these innocent murmurs. Sometimes they don't even recommend an echocardiographic examination, so we should probably do the same. If it is a soft murmur that changes with heart rate, perhaps we can wait for a few weeks or months and see whether there are changes.
If it persists, probably we need to consider either an echocardiographic examination or at least major in DNT Probnp and talk to me about.
[00:14:16] Michelle Meyer: I went to your lecturers this morning and you were talking about grade one to six that you're not using this grade reading scale anymore.
[00:14:23] Luca Ferasin: Well, we use it because I've got residents in training, so they need to learn the levine scale, the 1 to 6. But from a practical point of view, we don't need it. We can simply classify the murmurs in soft, moderate and loud and we achieve exactly the same clinical information because the Levine Scale is more than 100 years old. But that's not the problem. The problem is that it was designed for people and so it doesn't necessarily apply to dogs and cats. And I've got a problem with the 1 to 6 because for us it's bread and butter. We do it every day. But for vets working in general practice, with 300,000 of different things to consider, then perhaps the correct classification may the interpretation classification can be a little bit difficult to remember. So I think calling them soft, moderate and loud is much easier.
[00:15:21] Michelle Meyer: Do you ever find ECGs helpful for cats?
[00:15:24] Luca Ferasin: Well, obviously ECGs are very helpful if we're dealing with an arrhythmia. So every time we got an abnormal rhythm or perhaps the rhythm is too fast or too slow, then obviously ECG is the most important tool available. Although we don't do much interpretation of morphology of dcg, the rhythm can be assessed only by ecg, so it's something we run on a regular basis.
[00:15:51] Michelle Meyer: And I've had a lot of patients go to see the cardiologist and they have unclassified cardiomyopathy or I have a cat Mario cardiomyopathy as Mario disease.
So is the classifications hard sometimes in cats, they don't always fit in a bucket.
[00:16:05] Luca Ferasin: Yeah, well, I've got my own opinion. I don't really like to confine these conditions in a single group.
And there is such a wide phenotypical variations even within the same group of cardiomyopathy. So hcm, for example, can present in a multitude of different forms. The same applies to the other forms of cardiomyopathy. So I prefer to just describe what we see on echocardiophy rather than giving necessarily a name. If it Is a clear cut hcm, fine. But if it is something a little bit more complex with characteristics that can be similar to different types of cardiomyopathies, for example, you can have hypertrophy, but we can also have dilation. We can have fibrotic lesions that would apply to different forms of cardiomyopathy. My advice is just describe the lesions. Because if you describe the lesions, then you can pass this information to anyone else and they can understand. If we just give a name, the name can be interpreted in different ways. So I don't really like this obsession of giving a classification every time and actually call it unclassified.
We can make a joke about that. If we say unclassified, it's per se classification, so it's no longer unclassified. So we can carry on forever with this discussion because at the end of the day, we just need to describe what we see.
[00:17:32] Michelle Meyer: Okay, we all have, working in general practice, the cat that comes in that goes into respiratory distress. Can you talk me through what steps you would recommend to help stabilize that patient?
[00:17:42] Luca Ferasin: Yep.
Once you have a patient in respiratory distress, the first thing to do if this breathing difficulty is associated with anxiety, which is the majority of cases, sedation is the first thing to do. We need to avoid additional stress and give sedation to reduce the amount of stress. And that breaks that vicious circle of stress causing dyspnea and dyspnea causing stress, which if we leave it going, then it will spiral down the drain. And so we see cats in particular dying very rapidly because we don't intervene by breaking this vicious circle. So sedation is something that I was trying to dissuade in the past, but now with experience, I learned that it is the best intervention we can do, obviously combined with oxygen supplementation and with interventions to correct the underlying cause. So, for example, if you've got a pleural effusion, we need to drain. If we have pulmonary edema, we need to give diurese.
If we have an infection, because obviously dysne can be of a variety of different causes. Then we need to start with wide spectrum antibiotics. So we can obviously address this problem depending on the underlying condition. But certainly the first few steps are sedation, cage rest, oxygen supplementation, and then intervention to, if the cause is recognized, intervention to remove it.
[00:19:07] Michelle Meyer: Very helpful. Thank you. The last question I had, and this is the one that's hard, is a lot of cats have multiple diseases, and I have very often very itchy kitties with bad heart disease. And the only thing that works is steroids do you ever try a little dose of steroids to help these cats that are miserable with their dermatitis kind of issues? They can have steroids but need some.
[00:19:32]Luca Ferasin: Well, obviously you should never give up before giving steroids. That's the rule of old cardiologists, old clinicians like me. So steroids are always an option on the table.
The only problem I've got with steroids in cardiac patients is that they have the tendency to increase the plasma volume. And therefore, if you have a patient who is not in congestive heart failure yet but is on the edge, then the administration of steroids can just push.
They cut into failure, can tilt the balance very quickly. So we need to be ready. I'm not saying not to give steroids if they're needed, especially if there is a concomitant dermatitis or a GI issue. Whatever the reason is, we need just to be prepared to intervene with diuretics if they develop signs of congestive heart failure. So I'm not against it, but we need to be careful.
[00:20:20] Michelle Meyer: Short acting steroids, if anything.
[00:20:22] Luca Ferasin: Yes, yes, absolutely. Long acting steroids, a little bit more complicated to manage. But the principle is the same. If it happens that somebody is given a depo form of steroids and the cat develops congestive heart failure, then obviously we will deal with that by giving diuretics and controlling the plasma volume.
[00:20:43] Michelle Meyer: Very helpful. Thank you.
[00:20:45] Luca Ferasin: Thank you.
[00:20:46] Conclusion: Thank you for listening to this episode of All Cats Considered. We hope you enjoyed this interview. For more information on the topics discussed in this episode, please head over to catvets.com podcasts and explore the links in the show notes. Don't forget to subscribe to this podcast on your platform of choice so you won't miss any episodes as we release them. Have thoughts or ideas about the interview you heard today? Share them with us by leaving a comment on our Facebook page or shoot us an email@infoatvets.com thank you again for joining us today.
