Biology Reference
In-Depth Information
A few decades ago researchers discovered that dilated cardiomyopa-
thy is most often caused by a dietary deficiency of the amino acid tau-
rine.This discovery led pet food manufacturers to add more taurine to
cat foods, which virtually eliminated this heart problem.
Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is currently the most common
type of heart muscle disease. The cause is unknown, but the disease may
be the result of a congenital defect or may be acquired during a cat's life-
time. A cat with hypertrophic cardiomyopathy has thickened walls of the
left ventricle.This can also lead to thickening of other heart chamber walls.
As the wall thickens, the size of the chamber decreases and less blood
is pumped through the heart.Turbulence and pressure builds within the
heart, aggravates the condition and makes the thickening worse.
There are some drugs that can be used to reduce the stresses to the
heart and improve its function, but the disease cannot be cured. Cats
with HCM have shorter life spans because at some point the heart fails.
A complication of HCM in cats is aortic thrombosis or saddle
thrombus.This is a blood clot that forms in the heart and then becomes
trapped at the splitting of the aorta, where this large blood vessel sup-
plies blood to the rear legs. The prognosis for a cat with an aortic
thrombus is not good.Treatment may dissolve the clot, but the under-
lying heart disease cannot be stopped and will progress.
Cats with aortic thrombosis will suddenly become weak or para-
lyzed in their back legs due to the interrupted blood supply. This loss
of circulation is very painful to the animal. Less commonly, thrombi can
lodge and obstruct circulation to the front legs. A cat with a thrombus
will have cold, dark footpads and his toenails will not bleed where cir-
culation is lost.
Restrictive Cardiomyopathy
There are cats with heart muscle disease that does not classically fall
into either DCM or HCM. These animals are usually put in the cate-
gory of restrictive cardiomyopathy. Medications can be used to help
make the heart pump more effectively, but this disease will also progress.
HIGH BLOOD PRESSURE
For a long time, most veterinarians didn't know that feline high blood
pressure, or hypertension, existed because they didn't know how to
