Unless a heart murmur is the first thing diagnosed in a cat, usually heart disease is diagnosed when the cat is unable to breathe. Many pet owners may not have noticed that for a few days leading up to the moment they noticed the cat's inability to breathe, that the cat may not have been eating well, or may have been lethargic, or looked as if uncomfortable or in pain, or may have had to stop and rest often while walking or running, or may have been breathing rapidly while resting. A cat that is breathing rapidly in distress, will have while sleeping or while resting but not sleeping, rapid chest (or center of the body) heaving movements. It is rare that a cat will cough or will pant with its mouth open while in breathing distress but those should not be dismissed either. Another common sign that pet owners encounter is finding the cat is suddenly having a heart attack or a lame/paralyzed limb. These are caused by a blood clot that has formed in the heart and broken away and traveled through the body. Sometimes, pet owners come home and find that the cat has suddenly died.
In general, there are four types of heart disease seen in cats: HCM-hypertrophic cardiomyopathy, RCM-restrictive cardiomyopathy, DCM-dilated cardiomyopathy, and ARVC-Arrhythmogenic Right Ventricular Cardiomyopathy. While each affects the heart function differently and may have unique symptoms, all four affect the ability of the heart to fully function, can lead to congestion and impaired breathing ability, blood clots, heart attacks, and eventually death.
Damage to the Heart
Websites with Information Regarding HCM
Harpsie-a person's website about their HCM cat experience that discusses felinediseases with links to further information.
A vet's website regarding HCM in cats.
A link to Long Beach California vet hospital's discussion re: HCM. Useful terms, descriptions, and illustrations.
An older site from around 2007 with basic information and drawings and details.
A pamphlet with HCM information.
PetMD offers HCM information as well as general cat health information.
Cornell University College of Veterinary Medicine
University of Minnesota has a page with definitions and 3D imaging about the heart
Knowing and using medical terms will help you better discuss issues with the vet:
Medical terms to know.
Know, understand, and how to use medical measuring/dosing terms such as "q", "TID", etc.
This site offers information about understanding blood chemistry values.
A good source for definitions and terms relating to the heart and heart disease
A pet owner must be aware of many things affecting a cat that has heart disease: