Unless there is a holistic diagnosis it is not possible to gauge lifespan when a cat has a heart murmur and many with low-grade murmurs lead basically normal lives. Not all murmurs are serious and some are “functional” in which there is a normal amount of turbulence with no associated disease. The life expectancy of a cat with a heart murmur depends upon the seriousness of the murmur and the underlying illness if there is one. Veterinarians grade them from 1-6, with 6 being the most serious.
I’m trying to think of the occasion when a cat owner would be searching the Internet for an answer to the life expectancy of a cat with a heart murmur because, it seems to me, their veterinarian would tell them having diagnosed the condition. Perhaps some unqualified cat owners have detected a heart murmur. However, as expected, they are usually detected when a veterinarian listens to a cat’s heart using a stethoscope. There may also be symptoms if the heart murmur is clinically significant such as weight loss due to poor appetite, breathing problems, lethargy, and weakness.
As anybody can buy a quality stethoscope online, on Amazon, I suspect that cat owners are doing their own diagnosis and detected a heart murmur in their cat because they have noticed symptoms.
The problem appears to be that you need to be able to grade the severity of the murmur to assess lifespan and that would normally require the training and skill of a veterinarian. And you’ll need to diagnose underlying illnesses causing the heart condition. As a result, the answer that is required by a visitor to this page cannot be provided, sadly. It may be unwise to self-diagnose as there’s a need to diagnose holistically.
Heart murmurs are caused by turbulence in the blood flow through the heart. Birth defects and feline cardiomyopathy cause serious murmurs and hyperthyroidism can also cause heart murmurs. Other conditions with associated murmurs are systemic hypertension, which is high blood pressure and anaemias.
Source: Cat Owner’s Home Veterinary Handbook pages 312-314 & my thoughts.
SOME PAGES ON FELINE HEART DISEASE:
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