Kittens (like children) can have an innocent heart murmur which they grow
out of by about 6 months of age. I have Tansy who grew out of her murmur and her
heart scan was fine. But it can also be an indication of congenital heart
disease or early HCM. My vet usually relistens to the heart after a month to
see if the murmur is reducing, but if you are worried, you can get a scan done
by a cardiologist.
The disease which is responsible for fit young athletes to suddenly die is
to do with the electrical rhythms of the heart and isn't picked up as a murmur.
But Cardiomyopathy can also affect young people and can be picked up, and it
usually has symptoms.
I think everyone who takes on a pet may one day be faced with suddenly
coming home to find their beloved pet sick or passed. There's often no telling
which cats will develop HCM and which won't. Some cats live their whole lives
with a murmur. My mum's cat Minnie is 14 now and has had a murmur for 10 years.
I live every day with three young heart kittens who may or may not pass at
any time and see every day as a bonus. I wouldn't panic yet, as your kitten may
outgrow the murmur, but no one can ever say how long our pets will be with
us. Every day is a bonus. Also anaemia can cause a murmur too, and in their
condition, I would be suspicious of that.
My thoughts and prayers are with you and kittens.
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