Feline Cardiomyopathy is a disease that affects the heart muscle. There are three forms of Cardiomyopathy.
In Restrictive cardiomyopathy the heart fails to adequately pump blood due to scar tissue found on the heart muscle.
In Hypertonic cardiomyopathy the hearts does not pump blood properly due to a thickening of the heart walls.
In Dilated cardiomyopathy the walls of the heart swell to such an extent that the heart becomes enlarged and changes shape; it takes on a rounded shape, while the walls of the heart are severely are weakened because of it.
In all three forms, cats will suffer from improper oxygen distribution and eventually this disease will lead to death by heart attack.
Causes of Feline Cardiomyopathy
We now know that a deficiency of taurine which is an amino acid can cause cardiomyopathy. In the past commercial cats foods did not provide this essential ingredient but now the pet food providers are aware of the problem and have added taurine to their pet food brands.
Hyperthyroidism is caused from a thyroid growth (hyperthyroidism). It can also be caused by an over production of l-thyroxine which is a hormone produced by the thyroid (concurrent hyperthyroidism). This hormone will over stimulate the cat's metabolism. This condition is associated with the Hypertonic form of this disease. Cats that eat a lot of tuna, or diets rich in fish, as well as certain brands of canned cat food came down with this condition.
Diseases not confirmed but suspected to be a cause of cardiomyopathy:
There are also other causes that science has yet to discover, below is a list of some possibilities.
Kidney disease which is predominant in older cats can also be a trigger for cardiomyopathy whereby the heart becomes overtaxed, the walls may thicken (hypertonic) or enlarge (Dilated).
There is also a possibility that certain viral infections, lack of antioxidants, and genetics may be become triggers for cardiomyopthy.
Maine coon cats, Persians, and American Short hair cats have a predisposition towards this disease. Also, cardiomyopathy is found more among male cats.
Cats have a tendency to hit illness and when symptoms are detected it might appear that they surfaced rather quickly. The disease can take from a matter of weeks to several months before reaching a critical stage. The first signs of the disease will be loss of appetite, listlessness and inactivity. In the final stages of the disease before heart failure, these cats will be even more inactive. They have difficulty breathing due to lack of oxygen reaching the body tissues and the build up of fluid on the lungs.
The cats that are suspected of having cardiomyopathy are over five years old. An X-ray is the first test usually taken to back up the suspicion. Other tests that are used include: echocardiography or sonogram to hear the heart pumping, an ultrasound image of the heart to determine its size and shape and an EKG (electrocardiogram) for determining heart rhythm. Finally a test called A free T-4 level blood test will diagnose the presence of hyperthyroidism.
Veterinarians will determine the underlying conditions that brought on the cardiomyopathy. If it was due to hyperthyroidism medication can cure the disease. If not, specific drugs designed to address the specific form of cardiomyopathy will be administered. In addition to the medication addressing cardiomyopathy, cats with this disease also have blood clots descending the heart artery and require medication. It is common for a blot clot to form in the hind leg rendering the animal lame or paralyzed. When this happens the hind legs become very cold, and because there is a lack of oxygen, pads of the cat's feet take on a bluish colour. The feline is in extreme pain at this point and it is important to administer these drugs quickly to make the cat as comfortable as possible.
Generally speaking a cat will live up to three years after diagnosis; a little bit longer if the disease is determined even before symptoms occur. Good news for cats that have hyperthyroidism for they will return to normal after their hyperthyroidism is has been cured.