How to Treat the Most Common Feline Heart Condition
HCM, or hypertrophic cardiomyopathy, accounts for 80% of all heart problems in cats.
About 15% of cats develop heart disease, and of those, 80% develop hypertrophic cardiomyopathy (HCM), characterized by a thickening of the walls and ventricles of the heart, and an enlarged heart muscle
Symptoms of HCM depend on the severity of the disease; cats with heart murmurs, arrhythmias, or gallops should be evaluated for the condition
Diagnosing feline heart conditions can be challenging; fortunately, screening ultrasounds can help detect most significant disease, along with proBNP blood tests, routine blood pressure monitoring, and tests to evaluate cardiac muscle changes or increases in size
Recent research may help customize drug protocols for cats with HCM; a natural treatment protocol includes a combination of nutraceuticals, certain amino acids and heart glandulars
To help prevent heart disease in your cat, it’s important to feed a nutritionally optimal, species-specific diet supplemented with CoQ10 in the form of ubiquinol
Estimates are that about 15% of the general population of domestic cats are affected by heart disease.1 The condition most commonly seen in felines is hypertrophic cardiomyopathy (HCM), which accounts for 80% of heart problems in cats.2 Cardiomyopathies, which are disorders of the heart muscle that make it harder for the organ to pump blood efficiently, can cause heart failure or sudden death, even in younger cats.
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, when it comes to the heart, bigger isn’t better. The severity of the condition depends on how thick the muscle wall ultimately gets. Some cats develop only minor thickening, while others develop a much more significant problem.
As HCM progresses, the 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, and they 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 HCM patients, 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.
Ragdolls and Maine Coons are genetically predisposed to HCM (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.
Symptoms of hypertrophic cardiomyopathy in cats vary and depend to some extent on the severity of the disease. Cats with mild disease don't always have symptoms, but those with significant disease will usually show noticeable 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 compromised cat may have no or very mild symptoms that are non-specific and don't seem to suggest 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 with 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.
Diagnosing Feline Heart Disease Can Be Challenging
A heart murmur isn’t an accurate indicator of the presence of feline heart disease, because some cats have a murmur and some don’t, and in addition, cats can have a heart murmur but no heart disease.
When presented with a cat with suspected heart problems, many veterinarians refer the owner to a veterinary cardiologist, who uses ultrasound imaging to view the heart and diagnose disease. Sometimes kitties require light sedation to undergo an echocardiogram, and cardiac evaluations can run several hundred dollars.
The ‘Two-Minute Echo’ diagnostic ultrasound — Fortunately, in recent years smaller, less expensive ultrasound machines have come on the market, making them more accessible to general practice veterinarians. In 2016, veterinary researchers from Cummings School of Veterinary Medicine conducted a study to teach primary care veterinarians to use ultrasound to screen for heart disease in cats. The published results were encouraging.3
The Cummings team traveled around New England teaching veterinarians how to use an ultrasound machine and what to look for. They dubbed the screening ultrasound the “two-minute echo” because it takes just a couple of minutes and is also gentle on the cat.
After the training, veterinarians were able to identify the vast majority of asymptomatic kitties with significant heart disease. Unfortunately, the two-minute echo procedure isn’t as successful in helping to identify cats with mild heart disease. However, the veterinarians who were trained in the procedure told the researchers they planned to continue to screen cats for heart disease using the two-minute echo procedure.
The proBNP blood test — Heart murmurs, arrhythmias, or gallops detected in routine physical exams of healthy cats certainly warrant further investigation. If your veterinarian doesn’t have access to ultrasound as a diagnostic tool, I strongly encourage you to ask him or her to run a proBNP blood test on your cat.
This test can give you peace of mind that there are no early signs of heart disease, or it can alert you to a problem so that you can take steps to proactively manage your kitty’s heart health.
Routine blood pressure monitoring and blood test to check for changes or increases in the cardiac muscle — Dr. Betty Myers, a veterinarian in Amissville, VA explained in a local newspaper column her practice’s approach to catching heart disease early in cats:
“Routinely, we monitor blood pressure in our cats. We start early with this practice, sometimes even working with kittens, so the adult cat is unconcerned about having this done. Increasing blood pressure can be indicative of a problem other than high blood pressure (which is its own concern).
Additionally, we run a value on our bloodwork, including pre-anesthetic screens, that evaluates if the cardiac muscle changes/increases in size.
These two measurements, allowing us to monitor trends, help us decide whether an echocardiogram is indicated. This brief, non-invasive procedure is the best way to evaluate hearts and determine appropriate treatment. These tools extend animals’ lives and the quality of that life.”4
HCM 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. One of these drugs is clopidogrel (Plavix®), however, recent research shows that nearly 20% of cats with HCM show resistance to the medication.
A study at the University of California, Davis tested whether genetic mutations researchers identified within the drug pathway were responsible for reducing the drug’s effectiveness in some cats.5
“The end result is the ability to use a simple genetic test to make an educated decision about which drug therapy may be best for preventing blood clots in cats with HCM,” Josh Stern, professor of veterinary cardiology and geneticist with the UC Davis School of Veterinary Medicine said in a news release.6
The test isn’t yet commercially available, but the UC Davis researchers hope that eventually veterinarians will be able to rapidly test cats with HCM for these mutations as they are making prescribing decisions. It’s important to note that these drugs must be closely monitored to prevent hemorrhage, and they provide no guarantees.
I prefer to prevent the need for ACE inhibiting drugs by starting HCM patients on nattokinase to reduce the risk of blood clots. I have also found fucoidan, a polysaccharide extracted from brown seaweed, to be exceptional at preventing saddle thrombus, a condition that can occur in up to 25% of cats with HCM. Fucoidan also has blood thinning properties that your integrative vet will talk to you about.
Unfortunately, no medications have proved consistently effective in improving heart function in HCM patients. And sadly, often cats with HCM are not treated until congestive heart failure has developed.
I've successfully treated many patients with this heart condition 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, minimally processed meat-based diet, and eliminate all fillers such as grains and unnecessary carbohydrates.
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.
How to Help Prevent Heart Disease in Your Cat
Keep your feline family member lean by feeding a nutritionally optimal, species-specific diet that meets her nutritional requirements for unadulterated animal protein (amino acids).
Calculate carbohydrates (which cats don’t require) in your kitty’s food. Offer foods with less than 20% (and ideally less than 10%) so that the remaining calories come from lean proteins supplying abundant amino acids for heart health.
I believe the unnecessary carbohydrates found in most processed cat foods offset the amount of animal-derived protein cats need, making carbs (and nutrient deficiencies) a significant nutritional contributing factor to feline heart disease.
Also, the high temperatures the food is processed at inactivate the delicate fatty acids and B vitamins, so even though the label says it contains the correct amount of essential fatty acids and vitamins to maintain good cardiovascular health, they've been inactivated through the manufacturing process. Add in responsibly sourced krill oil at the time of feeding.
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 ultraprocessed foods and processing further diminishes their bioavailability. This is another reason I recommend minimally processed, starch-free foods (no grains or potatoes) for cats.
If you feed dry or canned food, I recommend supplementing your pet's diet with coenzyme Q10 (in the form of ubiquinol) and taurine, at a minimum, 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.
Healthypets Disclaimer: This information is for educational purposes only and is not intended to replace the advice of your own veterinarian or doctor. Dr. Karen Becker cannot answer specific questions about your pet's medical issues or make medical recommendations for your pet without first establishing a veterinarian-client-patient relationship. Your pet's medical protocol should be given by your holistic veterinarian.