A heart murmur can be determined as a swishing sound heard by the veterinarian when examining a cat. The murmur occurs because of a heart valve malfunctioning. A heart murmur isn't a disease in and of itself but does point to heart and other medical problems.
A heart valve can be too thick or damaged and as a result it doesn't close properly. When this happens blood will escape from the valve and spill into the surrounding areas. The swishing sound confirms that there is some kind of leakage going on at the time the value is closing (contracting). There are different classifications of heart murmurs depending on the turbulence (unsteady flow) and velocity, (speed of the blood flow).
The classification simple heart murmur is due to value malfunctioning. The classification functional heart murmur is due to valve problems and extracardial (outside the heart) factors, which could be other medical conditions.
A bacterium is a common cause preventing the heart value from closing properly. In older cats, the bacterial accumulation can be a result of poor dental hygiene.
Tachycardia - is condition where the heart beats usually fast.
In chronic causes of anemia, the feline may also acquire a heart murmur; the cause of this heart murmur is less serious than when it is directly due to heart valve problems. When the anemia is addressed the heart murmur usually goes away as well.
Pericardium effusion - abnormal amount of fluid (blood)in the dual-layered sac containing the heart.
Pleural effusion - abnormal amount of fluid (blood)in the pleural cavity which is the area surrounding the lungs.
Hyperthyroidism - where the body produces too much of the thyroid hormone which is responsible for regulation the body's physiological functioning.
Cardiomyopathy is most common in older cats. Cardiomyopathy is a result of a diseased heart muscle. There are three types of Cardiomyopathy,
Dilated (DCM), where the walls of the heart balloon and thin out.
Hypertrophic (HCM) where the walls thicken on the left side for a cat and this thickening also causes stiffness and interferes with the blood oxygenation process.
Idiopathic - is a catch all term for unknown cardiomyopathy of the heart muscle.
A heart murmur can be detected by the veterinarian using a simple stethoscope. In cases where the veterinarian believes that there is a serious concern for heart disease other diagnostic tools will be used. Your vet may take a urine sample; order a CBC blood test, echocardiogram, angiogram, and heart cauterization.
If cardiomyopathy - congestive heart failure is suspected, the veterinarian will also have an electrocardiogram and chest X-ray done as well.
Whooshing or swishing sound
When to take your cat to the veterinarian
If your kitten has a murmur it is not a cause for concern, but if the murmur is accompanied by other symptoms especially in older cats it is time to have your cat checked out. These symptoms could be; a cough, loss of appetite, lethargy, fever, lameness, or leg paralysis, respiratory problems, such as labored breathing and panting.
Many kittens are born with heart murmurs and outgrow them. It does not pose cause for concerns. However if the feline develops a murmur in its later years it may be time for concern. Some felines still live normal lives while others may develop congestive heart failure.
However, even with cardiomyopathy if this disease was detected before the symptoms presented themselves felines may still live a normal life, but if the disease was diagnosed in the advance stages, cats have on average three years before they develop heart failure and expire.
Remember even though a heart murmur alone is not cause for concern it is often indicative of a more serious underlying cause, never ignore the accompanying symptoms and get your cat to a veterinarian as soon as you notice them.