Genetic risks of HCM in Maine coon

[stevie_rae]

My 1.5 year old Maine coon died suddenly and I am devastated. On autopsy investigation, my vet concluded HCM due to enlarged heart (29g, normal around 20g) and increased ventricular free wall thickness (11mm, normal being around 5mm). We purchased from a reputable breeder who does DNA testing and annual ECG scans (which we received copies of when purchasing our cat). The breeder has graciously offered to provide us with another kitten despite being outside of the contract period.

The parent pairing are due for another litter. We would love to have a direct sibling as we think this will help with our loss, however, are there significant risk factors in getting another HCM cat from the same parents despite the testing that has been undertaken? I assume both parents have had updated ECGs which remain clear but I am still very concerned given the young age of the cat and the identified severity of the HCM.

Any insights would be appreciated.

 

[Alldara]

Even if the parents don't have it, doesn't mean they don't carry the genes for it. Every animal carries genes that they don't show.

Just like how two brown haired people can carry blond hair genes, if they had blond haired ancestors.

What are the chances? The breeder would have had to have kept track of all kittens to see how many had congenital heart issues and of those, how many had issues from it.

It's my understanding that HCM is common in Maine Coons. My half Maine Coon had a congenital heart murmur and out of all 5 kittens, only 2 lived past age 5. Nobel lived to 17. Then his HCM got worse.

 

[Maurey]

I am so extremely sorry for your loss, it's a very very tough thing.

That being said I would never get a kitten from the same pairing, nor support a breeder who wouldn't take out parents of a proven HCM kitten out of breeding. HCM is polygenic, and it means the parents have a risk of producing another kitten with the correct set of genes to have HCM.

Also, do they do ECG testing, or ultrasound testing? The former is relatively useless.

 

[Meowmee]

So sorry for your loss, it must be devastating.

I have been through hcm with two of my cats. Tess a domestic short hair who went into heart failure at eight years old, but she lived for 3 1/2 years and did relatively well until lasix damaged her kidneys. And my Sybil part nfc….hers did not show up until she was about 17 years old, and it was already very advanced so she did live a very long and happy life. I cannot imagine the pain you are feeling to lose a cat so young.

I definitely would not get a kitten from the same parents, and I agree that they should not breed those cats anymore. This condition is known to be hereditary in forest cats so the breeders are supposed to do whatever they can to avoid that.