Last month my article looked at how we can assess which large breed dogs are at risk from heart disease and ideally need echocardiography or ultrasound. A blood test called proBNP can help to identify those dogs most in need of a scan. This blood test (proBNP) is also extremely useful in cats. Cats are very good at hiding heart disease and this unfortunately can prove their downfall. Cats will live within their limits so as not to put any additional strain on their hearts. Unfortunately, this often delays diagnosing heart disease. This means cats present to their vets in a state of advanced heart failure and in crisis. Heart murmurs are one example of an early indicator which could avoid this happening.

So what are the signs we as owners should look for? The most common sign of heart disease in cats is an increase in respiratory rate. This is something that can easily be measured at home whilst your cat is resting or asleep. Count the number of breaths per minute and write it down. Periodically check this as any sudden (even subtle) changes should prompt a call to your vet. Other symptoms include breathlessness or resting after short periods of exercise, poor appetite and weight loss.

The most common cause of heart disease in cats is Hypertrophic Cardiomyopathy. This is a gradual thickening of the heart walls with eventual dilation of the chambers of the heart. It causes inefficiency of the heart as a pump. This may ultimately lead to fluid accumulating between the chest wall and the lungs preventing the lungs from fully expanding. Sometimes, fluid accumulates inside the lungs, increasing the respiratory rate to compensate.

Other early indicators your vet may find at a routine exam are heart murmurs. This is turbulence as blood moves through the heart. They may also find arrhythmias which are changes to the heart rhythm. These findings do not confirm heart disease but increase the suspicion for such and warrant further investigation.

The problem is many cats have heart murmurs, in fact, large studies across three rescue centres in London suggested up to 40% of cats have a murmur but only 15% of these cats had any significant heart disease when scanned. The presence of a murmur is certainly not a good reason to start medicating a cat for heart disease but it justifies further tests.

The proBNP blood test is available in cats as a ‘snap’ test. We can run this in the surgery, giving a positive or negative result almost instantly. The positive result increases the likelihood of underlying heart disease. We recommend that any cat with a murmur should be blood tested. Also, any cats with a positive proBNP result have an ultrasound. Knowing whether a cat has underlying heart disease is very important. Not only can we consider using preventative medication such as aspirin to reduce blood clots forming but we also know to avoid other medications such as steroids and only use intravenous fluids with extreme caution. It not only allows us to manage your cat’s heart disease but may change how we manage other illnesses, preventing potentially life-threatening complications too.