Heart Failure in Cats 101 (symptoms, complications, treatment + life expectancy)
Heart failure in cats is a difficult disease to pick up at home, and can be even harder to treat.
This is what you need to know about this challenging condition.
Next up is a question from Mary. She has a cat that's been diagnosed with heart failure that was only diagnosed when the disease was quite advanced. She is wondering if the disease really is irreversible, like she's been told. And also is it painful? Is it something that is causing pain to her cat? She's also asking what medication there is to treat it and then ultimately what the prognosis is?
Heart Failure in Cats
My first comment would be that cats are really good at hiding disease.
Often, especially with heart disease, it won't be picked up until late. So definitely don't feel guilty about not realizing that your cat was in heart failure. Cats will modify their behavior to hide their disease whereas a dog will run and run and then will collapse. A cat will just slowly reduce their activity levels. They may be sleeping more, they're not going to exercise and so you might not pick up anything. You're not going to pick up breathlessness or an exercise intolerance or an inability to chase a ball, because they just don't carry out those behaviors.
So don't worry and don't feel guilty about that, it’s very common.
Can heart failure be cured?
Now in most cases the changes are irreversible, especially when they're picked up late.
If it's early then it may at least be partly reversible if there is an underlying cause. So I guess the classic example of this would be a taurine deficiency, which we don't really worry about so much anymore because cat foods have extra taurine added to them because we know about this link. This was a problem I believe in the 1980s or earlier when we weren't aware that taurine was linked to heart health.
The other example where heart failure may be reversible in cats is an overactive thyroid or hyperthyroidism. Hyperthyroidism can cause heart disease, amongst other things, and if we're picking up this disease in the early stages and we’re then reversing that overactive thyroid, or that increased levels of thyroid hormone in the blood, then we could potentially reverse some of those changes within the heart.
Is heart disease painful?
Now as a condition, it's not painful. It causes a cat to be tired, to be weak, to be short of breath. Especially as it's getting worse and the lack of exercise isn't enough to compensate for the fact that the heart's not working well.
Now what is painful or what potentially is painful, is the risk of a blood clot forming and that blood clot then breaks off from within the heart where it blocks an artery. So actually the aorta, which is the main artery coming off the heart, is the most common location for this. The blood clot blocks the aorta or the vessels feeding off the aorta that go to the back legs. This is something called a saddle thrombus or an aortic thromboembolism, and is really painful.
What happens is the blood doesn't flow to the back legs and the muscle starts to die. It’s really painful.
Death through “drowning”
But the condition as a whole, it's not painful. It's going to affect the cat's quality of life and it's going to affect how they're feeling, but I guess pain itself isn't necessarily something that they're experiencing.
And then, if we're talking about the distress that heart disease and heart failure can cause, well at the end of the disease, when it's becoming all too much for the cat and the body to take, then effectively the lungs or the chest very often are filling up with fluid, ultimately causing suffocation and that can be very distressing for a cat as you can well understand.
Treating Heart Failure in Cats
Now, as far as treatment goes, I always struggle with treating cats with heart failure because there's not much good quality evidence that shows very much of what we do makes a really significant difference.
It could just be because we are often only treating cats with heart failure late in the disease process, when too much damage has already been done.
Often it can be very frustrating to treat, we're not getting the same response that we do in dogs with heart failure for example. But there are a few things that we can use, we do use and that I feel probably do make a difference.
So furosemide is one of those things. It’s a diuretic, which basically causes the kidney’s to pee out more fluid and so reduces the fluid build-up that we'd get in heart failure.
We can use something called pimobendan. This is a drug that may or may not help, but it can improve how well the heart contracts and how efficiently it works as a pump. It also reduces the oxygen demand of the heart.
We can use drugs like benazepril, or other drugs within this class which are called ace inhibitors. These can reduce salt retention and also fluid build-up, as well as reduce blood pressure, which again may or may not help.
And then the last thing that we think about would be something called clopidogrel. So I spoke about the aortic thromboembolism or saddle thrombus risk. Now that forms because we get turbulent blood flow within the heart, and effectively certain parts of the blood within the heart can actually become pretty stationary. This then allows little clots to form which can then form bigger clots which break away and cause those problems like we’ve discussed.
So clopidogrel actually stops those platelets clumping together, forming those little clots initially. We can give this drug to any cat with heart failure, but if we're having an ultrasound (known as an echocardiogram) performed to have a look at the structures within the heart and also to assess heart function, then what we sometimes see is something called smoke within the heart. This is the blood which is normally black actually becoming quite cloudy, which is these little clots forming already. So if that's the case, then definitely we should be reaching for this drug.
And lastly, which isn't in every case of heart failure, sometimes we'll have an irregularity in that heartbeat and a specific anti-arrhythmic treatment may be needed or something to try and get the heart rhythm back to normal.
Heart Failure Prognosis and Life Expectancy
And then finally, the prognosis and life expectancy is actually very varied.
So some cats, they'll only be presented when their chest is completely full of fluid. They're really struggling, their bodies are shutting down. In these cases they will die straight away, unfortunately, or they’ll be euthanized because they're struggling so much and we're not wanting to put them through too much.
In some cases though, where the disease is progressing very slowly, we might get a lot longer. In other cases, even if we're not getting it at that stage when they're on deaths door, it will progress very quickly and they'll go from being alright to very sick, pretty quickly.
Life expectancy for those not dying on presentation can be anywhere from about 6 - 18 months. It’s difficult to be any more specific than that.
The above is a transcript taken from “The Dr Alex Answers Show”.
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