Why Is This Potentially Deadly Heart Disease Overlooked Until It’s Too Late

Analysis by Dr. Karen Shaw Becker

heart disease in cats

Story at-a-glance -

  • Like dogs, cats can develop heart disease, most often a condition called hypertrophic cardiomyopathy (HCM)
  • In HCM, the walls and ventricles of the heart thicken, and the heart muscle enlarges
  • Symptoms of HCM vary and often depend on the severity of the disease; cats with heart murmurs, arrhythmias or gallops should absolutely be checked for the condition
  • Early detection is important, but unfortunately, many cats aren’t diagnosed until they develop congestive heart failure
  • There are things you can do at home to help your cat avoid heart disease; there is also a blood test available for early detection

Like dogs and humans, cats can also have heart disease, and in fact, it affects about 15 percent of the general population of domestic kitties.1

However, unlike the majority of canine heart patients, cats rarely develop degenerative valvular disease. The heart condition most commonly seen in felines rarely occurs in dogs. It’s called hypertrophic cardiomyopathy (HCM), and it accounts for 80 percent of feline heart problems.2

Maine Coons and Ragdolls are genetically predisposed to HCM, and there’s a genetic test available for these two breeds. The problem is also seen in the Persian, other oriental breeds and American shorthairs, but it can occur in any cat. Kitties usually develop the condition when they reach middle age, but it can occur at any age.

Two other types of cardiomyopathy — restrictive cardiomyopathy and dilated cardiomyopathy — are much less common in kitties. However, dilated cardiomyopathy (DCM) was quite common before a link was discovered between taurine deficiency and DCM around 1980. Now that taurine is routinely added to commercial cat food, the disease is seen far less in kitties.

Hypertrophic Cardiomyopathy Explained

Hypertrophic means thickened — the walls and ventricles of the heart become too thick, or hypertrophied, which causes growth of the heart muscle. Unlike other muscles of the body, in the case of the heart muscle, bigger isn’t better.

The severity of the condition depends on how thick the muscle wall ultimately gets. Some kitties develop only minor thickening; others develop a much more significant problem. As HCM progresses, the actual structure of the heart changes and heart function is affected. Thickened muscle walls become less flexible, and the left ventricle can no longer relax or stretch efficiently to fill with blood.

These changes can create a heart murmur because the heart valves don't grow as the heart muscle enlarges. The valves become insufficient. This can also cause a buildup of blood in the left atrium of the heart, which forces fluid back into the lungs and into the chest cavity, which ultimately causes congestive heart failure.

In some unlucky kitties, the thickening of the heart causes an arrhythmia that can bring on sudden death. And some cats develop feline aortic thromboembolism (FATE), also called saddle thrombus, which is a blood clot that forms in the aorta and blocks the flow of blood, usually to the back legs. FATE causes sudden paralysis, a tremendous amount of pain for the cat and even death.

Symptoms of HCM

Symptoms of feline HCM vary and depend to some extent on the severity of the disease. Cats with mild disease don't always have symptoms. But a kitty with significant disease will typically show obvious signs of a problem.

The challenge for pet parents is that cats are masters at disguising illness, so until the condition is severe, even a very sick cat may have no symptoms, or very mild symptoms that are nonspecific and don't seem to point to heart disease, such as a tendency to hide more, eat less or be generally lethargic.

In cats with obvious symptoms, there can be respiratory distress caused by congestive heart failure, or leg paralysis due to a blood clot as noted above.

Cats suffering congestive heart failure tend to breathe through an open mouth, and they sometimes pant. You should watch for breathing difficulties during exertion. Some kitties with HCM and congestive heart failure have a hard time walking any distance without stopping to rest.

Treatment Options

There is no cure for HCM, and changes that occur to the heart muscle are permanent. However, if the heart problem developed as a result of another underlying issue, treatment of the primary disease can result in partial or complete resolution of the HCM. Conventional treatment involves the use of diuretics and ACE inhibitors to treat congestive heart failure. Drugs that claim to reduce the likelihood of blood clots are sometimes used with HCM patients at risk for thromboembolism.

These drugs must be closely monitored to prevent hemorrhage, and they provide no guarantees, which is why I prefer to use the natural supplement nattokinase to reduce the risk of blood clots. No medications have proved consistently effective in improving the heart function in HCM patients. And unfortunately, often cats with HCM are not treated until congestive heart failure has developed.

I've successfully treated many kitties with this disorder using a combination of high doses of ubiquinol and omega-3 fatty acids, as well as certain amino acids, including taurine, L-arginine and acetyl L-carnitine. I also use heart glandulars and herbs, including hawthorn.

Because amino acid deficiency (a dietary shortage of meat-based protein) can fuel HCM, I strongly recommend that all my cat patients consume a human-grade, meat-based diet, and eliminate all fillers such as grains and unnecessary carbohydrates that kitties don't need in the first place.

I also think we’ve underestimated the role of vitamin D in companion animal medicine, and its role in heart disease, as well. Identifying and treating vitamin D deficiency is an important step in reducing diet-related cardiovascular stress.

Steps You Can Take to Help Protect Your Cat's Heart Health

Unfortunately, studies show that many apparently healthy cats have a heart condition. Heart murmurs, arrhythmias or gallops detected in routine physical exams of healthy cats certainly warrant further investigation.

I also strongly encourage you to ask your veterinarian to run a proBNP blood test on your kitty. This test can give you peace of mind that your kitty has no early signs of heart disease, or it can alert you to a problem so that you can take steps to proactively manage your cat's heart health.

In addition, keep your pet lean and fit by feeding a nutritionally balanced, species-appropriate diet that meets her nutritional requirements for optimal protein levels, healthy fat and coenzyme Q10. I believe the unnecessary carbohydrates found in most processed cat foods offset the amount of protein cats need, making carbs a significant nutritional contributing factor to feline heart disease.

Also, the high temperatures the food is processed at inactivates the delicate fatty acids, so even though the label says it contains the correct amount of essential fatty acids to maintain good cardiovascular health, they've been inactivated through the manufacturing process.

The amount of taurine, carnitine and CoQ10 found naturally in unprocessed meat is critically important to your kitty’s heart health. These vital nutrients are not found in adequate quantities in most dry foods, and processing further diminishes their bioavailability. This is another reason I recommend starch-free foods (no grains or potatoes) for cats.

If you feed dry or canned food, I recommend you supplement your pet's diet with coenzyme Q10 in the form of ubiquinol, as well as additional marine sources of omega-3 fatty acids (krill oil), especially if you have a cat that may be predisposed to cardiovascular disease.

Supplying your pet with extra CoQ10 (the reduced form) can ensure she has the quantity her body needs to maintain a healthy heart muscle.