Hypertrophic Cardiomyopathy is a genetic disease which affects cats, dogs,
pigs and people. How it is passed on in generations is still not clearly
discovered. Since the 1970's it is known that HCM is the common cause
for heart failure, thrombus and sudden death in cats. A major study has
been done on Maine Coon cats in the USA which indicates that HCM in these
cats seems to be inherited by a single dominant gene.
A healthy heart |
A HCM diagnosed heart |
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HCM is characterized by an abnormal thickness of the heartmuscle, mainly
at the height of the left side of the heart. Because of the thickening
of the heartmuscle the heart becomes less elastic, through which the heart
can fill itself less easy. A second consequence is that there is less
space for the blood left in the left ventricle, which causes a smaller
amount of blood to be pumped around at each heartbeat than normal. The
thick heartmuscle can create turbulence in the blood, or the leaking of
some valves. This can then cause a heartmurmur, which can be heard by
a vet with a stethoscope.
Cats with HCM can get fluid in or around their lungs which can lead to
difficult breathing. Other animals may show no signs at all, but they
can suddenly drop dead, mostly because of a sudden very severe rhythm
disturbance. Some cats develop blood clots that may cause paralysis of
the hind legs. HCM is not a congenital defect, but a disease that develops
very slowly. Cats that have HCM very often show no signs before they are
six months old, and it can take several years before you can make a diagnosis
of HCM. Therefore you must have a specialist performing an echocardiography
report on several occasions. The Swedish Maine Coon Cat Club has worked
out a HCM health programme starting on 1 January 2004. All breeds are
welcome to join the programme.
Is there a cure?
Unfortunately HCM can not be cured, but affected cats can be
treated with medication. Depending on the symptoms of the animal and the
state of the heart, diurectics, beta-receptor antagonists and/or ACE-inhibitors
will be used.
How is a HCM test performed?
The cat is examined using an ultrasound machine (echocardiographic test)
where you can see if there are any abnormally thickened parts, how the
heart beats and how the blood flows. The examination is painless and is
usually tolerated very well by the cats. If the cat feels uneasy, it would
be better giving the cat a slight sedation (injection) as it is important
that the cat lies still on the examination table.
Sometimes it is necessary to shave the cat a little just on the spot where
it is going to be examined. In other cats it works very well just spreading
the fur apart without having to shave. In order to get good contact with
the cat’s skin and also a good picture of the examined area jelly
is being used. The examination lasts for about 30-40 minutes.
Click here to learn more about
how to proceed for HCM-testing your cat.
Click here to read about the
recommendations on testing and breeding regarding HCM.
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