Heart disease is a relatively common health concern in middle-aged-to-elderly dogs and cats. Its symptoms can be subtle: lethargy, coughing, and labored breathing. Not all pets with heart conditions have an audible murmur when they're examined with a stethoscope, so this can make diagnosis in the early stages of their disease quite difficult. This is particularly the case in cats; they can seem to be healthy on the outside while their heart isn't working quite as well.
Cats tend to suffer from diseases of the heart muscle known as cardiomyopathy. The most common type of cardiomyopathy is hypertrophic cardiomyopathy where the left ventricle wall becomes thickened and can't relax and fill properly. The result is poor circulation, development of congestive heart failure, and a risk of blood clots developing in their aorta that block blood flow to their hind legs.
Most cases of heart disease in dogs have a different cause. Abnormalities of the mitral valve, which controls blood flow between the left atrium and ventricle, can lead to heart failure. In these cases, it's not uncommon to hear an audible heart murmur.
Treatment for heart disease needs to start when the heart starts to fail. This means that pet parents need to be watchful for the early signs of this disease so they can give their pets medication to support their circulation. This isn't always easy because early signs can be missed.
A new blood test is available to evaluate a pet's heart health. The proBNP test measures levels of a protein in the blood that's associated with heart damage. This protein is produced in the heart's muscle cells and is released in proportion to the degree of heart muscle stretching. This means that as heart disease progresses, the blood levels of the hormone increases. It's a particularly useful test for cats because they may not show signs of disease until their condition is quite severe.
The proPNP test is a quick and easy way to check a pet's heart health. However, on its own, it's not enough to evaluate properly how well a heart is functioning. If a pet has an abnormal test result, then it's appropriate to move on to further tests, including ultrasound of the heart to ascertain blood flow abnormalities.
There are many causes of the symptoms that we usually see with heart failure. Coughing and lethargy can also be associated with respiratory disease, so it's not always easy to work out what's going on. The proBNP test is a convenient tool to evaluate whether a pet's cough and lethargy is related to their heart or if it's caused by another medical condition. It can also give a pet parent early notification that something is wrong with their pet's heart and that heart failure may occur in the near future. This allows them to be more watchful for symptoms of heart failure so that affected pets can start treatment straight away and enjoy a better quality of life for longer.