Feline Cardiomyopathy


The term cardiomyopathy means disease of the heart muscle and it is a useful phrase to cover all heart problems which do not have any other cause that can be identified. Older cats are often diagnosed with heart failure and increasing numbers do not mean that it is getting more common but simply that more cats are living longer and that diagnostic techniques are improving. It used to be very difficult to measure blood pressure in cats, but better technology has made it relatively simple and now a blood pressure check is a basic in any check up on an older cat. They frequently have kidney problems, which puts a strain on the heart, so hypertension, discovered early, can prevent the collapse that used to be such a distressing cause of death in old cats.

Symptoms of cardiomyopathy

Symptoms will vary widely depending on the problem with the heart but lethargy is often a first sign. Onset can be quite sudden and be close to collapse, and if the problem is a clot, usually caused by pooling blood in a poorly beating heart, the back end of the cat can suddenly fail, with a stiff, cold tail and hind legs, which are clearly painful when touched. If the cardiomyopathy is because of congestive heart failure onset is often slower, but again can come on very suddenly, with breathlessness and collapse. In this case, the heart cannot beat properly, fluid gathers around the lungs and so oxygen does not get round the tissues properly and so the animal will pant to try and make up the deficit. Apart from the symptoms and sudden onset conditions there are also symptoms which you might not immediately associate with heart disease.

Kidney function becomes disturbed when high blood pressure interferes with the filtration of urine and also a cat can suddenly go blind, as hypertension can cause detachment of the retina. It may take you a few minutes to realise that your cat has gone suddenly blind, as its behaviour will suggest a seizure or something similar as it may panic with the sudden disorientation. All in all, a cat with cardiomyopathy is generally a very sick animal indeed.

Treatment of heart problems in cats

Treatment will very much depend on the general health of the cat apart from the heart problem and also the exact type of cardiomyopathy which is affecting the animal. In general, though, it is important to reduce pleural effusion so that the lungs can work better, putting less strain on the heart. This is usually done through administration of diuretics, as long as the cat is not renal impaired. In that case, the fluid can be drained by a catheter through the chest wall, which can be left indwelling until the situation has eased. Depending on the diagnosed cause of the cardiomyopathy there are a variety of drugs which can be used, but again the general condition of the cat will have a bearing on their use. Beta blockers are often used if the heart is racing.

In cases with a rapid heartbeat the heart can ‘flutter’ because the chambers are not filling and emptying completely in the time between beats, so this can buy valuable time for further investigations or just to make the animal more comfortable. Aspirin, or in serious cases, heparin can be given to prevent clotting and finally if the cat has high blood pressure, drugs are given to bring it down or in the case of an animal on medication already, the dose can be adjusted. Some of these treatments can be considered last resorts and are not always successful.


There is no hard and fast rule governing the likely recovery of a cat with cardiomyopathy. If it is secondary to another condition, such as a thyroid problem or a transient respiratory issue then it can usually be resolved although the cat should always be considered at risk in the future. If the heart itself is the seat of the problem and particularly if there is a clotting tendency, then the outlook is not so good. As in humans, diet can help and keeping salt low is one of the ways in which hypertension can be partially eliminated. Many cat treats are quite high in salt, so they particularly should be avoided. Keeping the cat within reasonable parameters for weight is also a good measure, which should be a lifelong aim for the owner of the cat, not something which is only addressed after a cardiac problem has arisen.

Not all cats are avid hunters or keen on exercise and if the cat is kept indoors it is sometimes difficult to keep it mobile and therefore reasonably fit. There are lots of cat toys on the market to amuse them, and it is not difficult to find one which makes the animal run about. Even a feather on a string (with a human on the other end, preferably) can give a cat a good workout. Finally, some breeds are a little more prone to heart problems than others. While this should not be a reason for not owning one – for example Maine Coon and Ragdoll – forewarned is forearmed and any sign of trouble should be the flag that triggers a trip to the vet.


You can now get advice online 24/7 from a qualified vet: Ask a Vet Online Now

Close Bitnami banner