Hereditary diseases: Hypertrophic Cardiomyopathy (HCM)

Hypertrophic Cardiomyopahy (HCM) is a heart condition in all breeds of cats (and random bred cats) which causes the wall of the heart left ventricle to thicken progressively as the cat gets older. This means, eventually, that the heart may not be able to function efficiently and the thickening can progress until the cat life cannot be supported. Too many cats die from HCM each year.

There is no cure for HCM. HCM is a genetic condition and can be inherited.

Until recently, HCM could onlybe diagnosedby a scan of the heart or by a necropsy; however, sometimes a slow progression of HCM may not show up on a scan for years. This means that there is no sure way to tell if a breeding cat is free of HCM until the cat is older and has already started breeding and may then pass it to the kittens.

The Ragdoll and Maine Coon breeds have been now studied in connection with feline HCM. Recently, there was a major breakthrough when one of the genes for HCM in our Ragdolls was identified.There are a number of genes which can be the source of HCM in cats, so that wonderful success does not end the search.

HCM has been identified in many breeds and in random bred cats. Ragdolls are one breed in which HCM has been found. The research on HCM in Maine Coons and Ragdollshas helped understand, diagnosis, and treat the condition in Ragdolls and other cats. No doubt research of HCM in Ragdolls will also benefit all other cats.

Kathryn M Meurs, DVM, PhD, Diplomate ACVIM (Cardiology), who led the effort to find the recently discovered HCM gene in the Maine Coon, has now found an HCM gene in Ragdolls. A DNA test for the Ragdoll mutation is now available. All Ragdolls used as breeders should not be screened with the DNA tests for the Ragdoll Mutation and the Maine Coon mutation.

With this test,we can start testing our Ragdoll breeding cats for HCM before they are bred. Each gene that is identified means that breeders can avoid producing kittens with that genetic defect. When all the genes are identified, we will no longer risk having kittens born who have inherited HCM.