Cardiomyopathy is a common and very serious cardiovascular disease affecting the heart muscle. The actual cause of Cardiomyopathy in cats and dogs is not known, however, in some cases it is due to a deficiency of taurine (a sulfur-containing amino acid important in the metabolism of fats). Additionally, cats and dogs may develop the disease simply due to genetics.
In cats, the disease causes the walls of the heart to become thickened, decreasing efficiency, which can sometimes create symptoms with other parts of the body. The cat’s heart can begin to beat rapidly, and can eventually lead to the development of arrhythmias, congestive heart failure and blood clots formed in the heart. Most often, these clots will cut off the blood supply to the hind limbs, which can be very painful or result in paralysis in extreme cases.
In dogs, this disease causes the chambers of the heart to become enlarged, preventing them from functioning properly. The heart will progressively worsen and deteriorate to the point that it is unable to effectively pump enough blood to the lungs and body. As a result, fluid builds up in the lungs, causing Congestive Heart Failure (CHF).
The best way to diagnose cardiomyopathy is to have an echocardiogram (ultrasound of the heart) done by a cardiologist to evaluate heart function. However, while cardiologists can detect the disease before any physical signs are noticed, there is currently no cure for this disease.
Symptoms in cats can include rapid or shallow breathing, or overall difficulty breathing (breathing with their mouths open), lethargy and blood clots (mentioned above). However, many cats with hypertrophic cardiomyopathy do not show symptoms.
Symptoms in dogs can include coughing (especially at night), excessive throat clearing, rapid or shallow breathing, difficulty breathing, excessive panting, lethargy, reluctance to exercise, weight loss, swollen stomach, fainting or collapsing, arrhythmia (abnormal heart rhythm) and heart murmurs (an unusual sound heard between heartbeats; a rasping, whooshing sound).
Cat breeds genetically predisposed to Cardiomyopathy (possibly due to mutations in certain cardiac genes), are the British Shorthair, Chartreux, Maine Coon, Persian, Ragdoll and Sphynx. The British Shorthair, Sphynx, and Chartreux are more likely to develop hypertrophic cardiomyopathy.
Dog breeds genetically predisposed to Cardiomyopathy are the Afghan Hound, Boxer, Cocker Spaniel, Doberman Pinscher, English Cocker Spaniel, Great Dane, Irish Wolfhound, Newfoundland, Saint Bernard, Scottish Deerhound and Sussex Spaniel. It is mainly seen in large breed adult dogs; however, the Cocker Spaniels are at a greater than average risk of being affected by Cardiomyopathy.
Early diagnosis is the key factor in successfully treating this disease.
Common Treatment Protocol
For cats, drugs can be prescribed to help slow down a rapid heartbeat, and diuretics can help control the fluid buildup in the lungs (congestive heart failure), as well as help prevent blood clots from forming. The cat will still need rechecks to track the progression of the disease. These rechecks will involve ultrasounds of the heart and EKGs. The cat will need to be monitored closely at home as well. It is worth noting that hypertrophic cardiomyopathy is a disease that gets progressively worse over time.
For dogs, drugs are usually prescribed to help the heart contract better, or to slow down a rapid heartbeat. Diuretics are used to control the fluid buildup in the lungs, while other drugs are used to dilate the blood vessels to help with the dog’s circulation. The dog will need to go on a low sodium diet and have rechecks to track the progression of the disease. These rechecks will involve ultrasounds and possibly radiographs of the heart, along with EKGs. The dog will need to be monitored closely at home as well. Even with all this, most often the prognosis is poor.
Cardiomyopathy can be treated with stem cells by injecting them directly into the heart muscle, into the pericardial sac or into the coronary arteries. These cells release cytokines (growth factors) which help repair damaged heart muscle and regenerate lost heart cells. In human studies increased exercise tolerance and longevity are associated with administering stem cells. Giving cells earlier rather than later is always more effective.
The cost of drugs for pets with cardiomyopathy can be quite expensive, because they will need to continue taking the prescribed medication for the remainder of their life. In addition, clinic rechecks may include costly ultrasounds and/or EKGs.