Hypertrophic Cardiomyopathy is the most common haert disease in cats and is seen at almost any age. A pattern of inheritance in families of cats strongly indicates an autosomal dominant mode of inheritance, as is the case with humans. Up till now no viral disease or dietary causes of HCM have been identified in humans or animals
As HCM developes and progresses,
it alters the structure of the heart and impairs its function in several ways.
The muscular walls of the ventricles (upper chambers of the heart) become
abnormally thickened. The thickened walls become stiff, making it more difficult
to fill with blood. The stiffness causes accumulation of fluid and pression
of the blood in the longs and causes shortness of breath. There is a great
chance in getting thrombosis.
Symptomen can be: cardiac murmur, a gallop rythm, tightness of the chest, indolence, paralysis of the back feet, vomit, lose in weight, etc
There's no cure for HCM, but with medications the life of the cat can be stretched.
On the left picture the profile of a healthy heart. On the right picture the profile of a HCM-heart shows the thickness of the muscular wall of the ventricles.
HCM can disappear only by excluding HCM affected cats from breeding. With an echocardiogram (an ultrasound of the heart) HCM can be noticed.
Nowadays it is possible to examine
the DNA on the presence of HCM1, a variant of HCM. A negative result is no
guarantee that the animal is not affected at all, because there are more variants
of HCM. Examination on HCM every year by an echocardiogram stays necessary.
There are two possible results by examining the heart with an echocardiogram: Negative or positive.
With a DNA-test there are three possibilities:
1. hcm/hcm or neg/neg (negative), the animal is free from HCM;,
2. HCM/hcm or pos/het (positive/heterozygote), the animal has one defective allele, it will develope HCM later in life, it wil also pass through the defective allele on half of the descendants;
3. HCM/HCM or pos/hom (positive/homogyzote), the animal has two defective alleles, it will become ill and die on HCM, it will pass through the disease on all of the descendants.
The Ragdoll Club Benelux has decided to put on the list of studs only HCM-PKD-negative cats. A very good measure.
Over the hereditary nephropathy PKD I did (with permission) copy the primary points from the Neocat Magazine.
Polycystic Kidney Disease (PKD) means literal : "Renal disease with many liquid bubbles'.
As HCM PKD is also a disease that in all cats can precent, but particularly in Iranians. From the urinary discharge pipe are growing cysts and the normal renal tissues come in opression. If only a limited number of cysts is emergenced or only one kidney is affected the animal will not fall ill, but the descendants all will have the disease, fall ill and will die. Though the cats need not themselves to be or fall ill to pass through the disease on their descendants. There is no cure. A diet food can be given with a decreased amount of protein and phosphates, but the kidneys will operate worse and worse and at last euthanasia wil have to be passed.
There are several renal diseases that will cause real failure, but to determine the heridatery PKD or another form of a not-heridatery renal disease an echografical investigation is necessary. In a positive deflection of the examination the cat has to be excluded from breeding.
The black spots showed by this echogram are cysts,
bubbles filled with liquid.