Heart Disease in Maine Coons (HCM)
Vet-reviewed via PetHealth+ · Last reviewed June 2026
Maine Coons are genetically predisposed to HCM — thickening of the heart muscle. Screening breeding cats and periodic heart scans help.
Signs
May be silent until advanced — lethargy, rapid breathing, collapse.
Screening
Echocardiography detects early changes.
Treatment
Medication slows progression when diagnosed.
Related: Maine Coon breed guide
Frequently asked questions
At what age should Maine Coons be screened?
Breeding cats before mating; pet cats as advised by your vet.
Is HCM curable?
No — but medication can manage symptoms.
Do all Maine Coons get HCM?
No — but prevalence is higher than in many breeds.
Can a normal cat develop HCM later?
Yes — repeat screening may be advised for breeding lines.