What is cardiomyopathy?
Cardiomyopathy is a term used to describe diseases of the heart muscle. Cats can suffer from primary cardiomyopathy, or they can get cardiomyopathy as a result of another illness. In either case, it can lead to heart failure.
What symptoms indicate my cat might have cardiomyopathy?
Early on, there won’t be any symptoms. As the disease progresses, your cat will adjust her activities to compensate for cardiomyopathy. In fact, your cat will probably not have any symptoms until the disease is advanced. At that point, you may notice rapid or difficult breathing, loss of appetite, lethargy or loss of the use of her back legs.
What causes the symptoms of advanced cardiomyopathy?
- The breathing problems, loss of appetite and lack of energy are because your cat’s heart cannot pump very well. Fluid backs up into her lungs, just like it does in people.
- Sometimes the blood flow within your cat’s heart gets stagnant enough that clots form. If a clot breaks off and travels through the body, it may lodge at the bottom of the aorta and block circulation to her legs. This is an extremely painful and possibly fatal complication of cardiomyopathy.
How is cardiomyopathy diagnosed?
Your veterinarian may suspect that your cat has cardiomyopathy based on his symptoms. Your vet may perform the following tests to confirm the diagnosis:
- Chest x-ray
- Electrocardiogram (ECG). The ECG isn’t very helpful in diagnosing cardiomyopathy, but it will help determine if there are any other heart problems.
- Cardiac ultrasound. This helps determine which kind of cardiomyopathy your cat has (there are at least three major types).
- Specific tests to determine if another disease is causing the cardiomyopathy.
What causes cardiomyopathy?
There are many causes of cardiomyopathy. The most frequently seen ones are:
- Thyroid disease (hyperthyroidism). This is most often seen in older cats.
- Taurine deficiency. Taurine is an essential nutrient for cats. Taurine deficiency is rarely seen in cats who are fed fresh meat or commercial cat food.
- Idiopathic cardiomyopathy. That means that no cause can be found.
How is cardiomyopathy treated?
If an underlying cause is found, that is treated first. Sometimes that is all the treatment that is needed. Hyperthyroidism is the most treatable cause of cardiomyopathy, and treating the thyroid problem can cure the cardiomyopathy.
If no cause is found, or if treating the cause doesn’t help, your vet may suggest different medications.
- Diuretics for congestive heart failure
- ACE inhibitors—another medication for congestive heart failure.
- Beta blockers and calcium channel blockers—to regulate the heart rate and help the heart muscle relax
- Aspirin—to decrease the risk of clots. Aspirin is not always used because aspirin can be toxic to cats, and the dose has to be carefully regulated. DO NOT give your cat aspirin without a veterinarian’s advice.
Does a cat with cardiomyopathy need a special diet?
For most cats with cardiomyopathy we recommend moderate salt restriction. The diets that best meet this requirement are diets for senior cats and diets for kidney disease. If your cat has taurine deficient cardiomyopathy then taurine supplementation will be necessary. Many cat treats that are sold are very high in salt and are probably best avoided.
What is the prognosis for a cat with cardiomyopathy?
The prognosis depends on what caused the cardiomyopathy and how advanced it is. Some cats remain stable and live near-normal lives for several years after being diagnosed with cardiomyopathy.