Heart disease isn’t just a human problem. Our pets can suffer too, and cats in particular are susceptible to something called hypertrophic cardiomyopathy, or HCM. Cats are notoriously good at hiding when they are sick or in pain. This can make it very difficult to notice the signs of cat hypertrophic cardiomyopathy. This short guide to feline HCM explains what the condition is, what to look out for and how it might be treated by your vet.
Cat Hypertrophic Cardiomyopathy: What is it?
Hypertrophy is a thickening of muscle, so HCM means the heart muscle itself becomes thicker and stiffer. This means the ventricles in the heart don’t perform well, as they never fully relax. This reduces the amount of blood pumped into your cat’s circulation with each beat of the heart.
No one knows what the cause of cat hypertrophic cardiomyopathy is, but there is some speculation that certain cats may be genetically predisposed to the condition. The massive Maine Coon cats, and the longhair Ragdoll breeds are both noted as being susceptible to feline HCM. Norwegian Forest Cats and Sphynx cats may be at risk too. The condition normally appears from middle age onwards, and is much more common in older cats.
Cat Hypertrophic Cardiomyopathy: Signs and Symptoms
In the early days of HCM, your cat may show no signs at all of any problem. This is because the thickening of the heart muscle begins gradually. Once the condition has advanced, it begins to cause congestive heart failure, causing fluid to build up around the lungs. The symptoms of this include lethargy and decreased activity level, so if your normally playful and energetic cat is suddenly slow and tired, it’s time to see a vet. Other symptoms include breathing issues and panting, particularly after exertion. Your cat might lose their appetite or have otherwise unexplainable weight loss.
One rare complication of cat hypertrophic cardiomyopathy is a blood clot forming in the heart and entering the cat’s circulation. This can cause paralysis, particularly in the rear legs. If your cat’s mobility is suddenly reduced, seek medical attention from a vet immediately.
Cat Hypertrophic Cardiomyopathy: Diagnosis and Treatment
Once you’ve discussed the symptoms, your vet will do several tests. These may include a chest x-ray, to check for any build-up of fluid. They might use an electrocardiogram (ECG) to check the heart’s rhythm. Blood tests are taken and checked for indicators for thyroid and kidney issues too. Cat hypertrophic cardiomyopathy can arise as a secondary condition of thyroid or other internal problems, so your vet may often do a full physical check-up to rule these other issues out. An important test is an echocardiogram to measure the size and function of the heart. This allows the vet to inspect any physical abnormalities in the heart valves. Your cat’s blood pressure will be closely monitored throughout.
Feline HCM isn’t curable, but can be managed with care and medication. Your cat might be hospitalized during testing and initial medications. Once your cat is out of immediate danger, your vet will discuss ongoing treatment with you. There will usually be heart medication to slow the heart rate and improve blood flow. There may also be medication to prevent blood clots, and you may need to adjust your cat’s diet to maximize their overall health.
Although cat hypertrophic cardiomyopathy sounds scary, with proper care and timely intervention the prognosis looks good for many cats. Always speak to your vet if you have any concerns.