By Dr. Becker
Today we're going to discuss feline cardiomyopathy.
Cardiomyopathy is a big fancy word.
But you can break it down to "cardio" (meaning heart), "myo" (the Latin word for muscle), and "pathy," which means disease.
So what you have is a disease of the heart muscle
There are different kinds of cardiomyopathy, including hypertrophic cardiomyopathy, dilated cardiomyopathy, restrictive cardiomyopathy, and unclassified cardiomyopathy.
Hypertrophic cardiomyopathy, or HCM, is the most common acquired heart disease in cats, and that's what I'll be talking about today.
Hypertrophic cardiomyopathy is common in cats, but rarely seen in dogs.
Dogs tend to acquire dilated cardiomyopathy, which I'll discuss in a future video.
The word "hypertrophic" means thickened, so this is a condition where the walls and ventricles of the heart become much too thick, or hypertrophied. Several other diseases also cause thickening of the left ventricular wall, including aortic stenosis, hyperthyroidism, and systemic hypertension (high blood pressure). HCM is diagnosed once other causes have been ruled out.
HCM is often inherited in cats. In fact, there's a test available now for a specific gene mutation in Maine Coons and ragdolls. Purebred cats such as the Persian, other oriental breeds, and American shorthairs are also predisposed to develop the condition.
However, it's the regular house cat that is most commonly diagnosed with HCM. Cats usually develop the condition in midlife, but it can occur at any age.
How HCM Damages the Heart
When you work a muscle it gets bigger, and that's a good thing, right? It is – except in the case of the heart muscle.
The thickening that occurs with HCM and causes growth of the heart muscle isn't normal or desired. 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 cats, thankfully not many, the thickening of the heart causes an arrhythmia that can bring on sudden death. And some kitties develop feline aortic thromboembolism, also called FATE, which is a blood clot that forms in the aorta and blocks the flow of blood, usually to the back legs.
Needless to say, this causes sudden paralysis, a tremendous amount of pain for the cat, and even death.
Symptoms of feline hypertrophic cardiomyopathy vary and depend to some extent on the severity of the disease. Cats with mild disease don't necessarily have symptoms. But in a kitty with significant HCM, there are usually obvious signs.
As we know, kitties mask illnesses very well. So until this condition is severe, even a cat with significant disease may have no symptoms, or very mild symptoms that don't seem to be indicative of heart disease.
In cats with obvious symptoms, there can be respiratory distress caused by congestive heart failure, or leg paralysis due to a blood clot.
Cats suffering congestive heart failure don't cough like people or dogs do. Instead, they tend to breathe through an open mouth, and there can even be some panting. 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 and recuperate.
Diagnosis of HCM
Kitties with hypertrophic cardiomyopathy often have a problem called systolic anterior motion (SAM) of the mitral valve. This abnormal motion of the valve obstructs blood flow and can result in a murmur that can be heard with a stethoscope. Sometimes vets can preliminarily diagnose HCM early in the disease process just by listening for a murmur.
A cat with HCM who is having trouble breathing or loses function in his front or back legs should be seen immediately by a veterinarian so he can receive necessary treatments like oxygen therapy, anticoagulation medication, and/or pain medication.
The best way to diagnose HCM is with a non-invasive ultrasound, which is also called an echocardiogram of the heart. This is done with color flow and spectral Doppler imaging, which is a three-dimensional picture that allows the vet to visualize the structure and function of the heart.
An EKG or electrocardiogram and X-rays can provide additional information, but should not be used alone to diagnose this condition.
Treatment Options for Kitties with HCM
At the current time there is no cure for HCM. Changes that occur to the heart muscle are permanent. But if your kitty's heart problem has developed as a result of another underlying issue, treatment of the primary disease can result in partial or complete resolution of the HCM.
Diuretics and ACE inhibitors are used to treat congestive heart failure in cats. In cases of severe fluid buildup in the chest cavity, the vet may need to remove the fluid with a catheter to help the animal breathe more easily.
Drugs that claim to reduce the likelihood of blood clots are sometimes used on HCM patients at risk for thromboembolism. These drugs must be closely monitored to prevent hemorrhage, and there's no guarantee blood clots won't form even with the medications. Needless to say, rather than anti-clotting drugs (and their side effects), I much prefer using a natural supplement called nattokinase to reduce the risk of blood clots.
No drugs 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 see many kitties in my practice with this disorder, and I've had excellent success not only slowing the disease, but actually improving ultrasound measurements using a combination of ubiquinol and certain amino acids, including taurine, L-arginine, and acetyl L-carnitine.
I also use heart glandulars and herbs, including hawthorn.
This condition, in my opinion, is rooted in Nutrigenomics. Nutrigenomics is the study of how foods can upregulate or down regulate gene expression. Because amino acid deficiency (a dietary shortage of meat-based protein) can fuel this condition, I strongly recommend all my patients consume a human-grade, meat-based diet, and eliminate all fillers such as grains and unnecessary carbohydrates that cats don't need in the first place.
The prognosis for cats with hypertrophic cardiomyopathy is highly variable. Some kitties develop only mild thickening of the heart walls and lose very little function, while others develop really significant disease.
HCM can progress quickly over a period of months or quite slowly over several years. A mild case can be unchanged for many years and then suddenly progress in severity.
The risk of congestive heart failure depends on the severity of the HCM. Cats with heart failure have a poor prognosis, so my recommendation is to begin a supportive protocol as soon as possible. Early diagnosis coupled with a proactive healing protocol can afford cats the very best opportunity to slow progressive cardiac changes and maintain an excellent quality of life.