Cardiomyopathy, “disease of the heart muscle,” is caused by a primary structural or functional abnormality of heart muscle caused in most cases by an inherent genetic abnormality. Cardiomyopathy most frequently results in the heart muscle growing too thick to function normally. Less commonly, the heart muscle becomes too thin and does not contract normally. The abnormality, in either case, alters the hearts ability to both collect blood from and pump blood to the body which often leads to congestive heart failure with respiratory distress, paralysis-causing blood clots, and, in some cases, sudden death.

Cardiomyopathy occurs more often in young adult cats, although younger cats as well as seniors are also susceptible. The condition more commonly affects males.

Most Common Types of Cardiomyopathy

  • Hypertrophic
  • Hypertrophic obstructive
  • Restrictive/Intergrade
  • Dilated


  • Loss of appetite
  • Lethargy
  • Difficulty breathing
  • Inability to tolerate exercise or exertion
  • Sudden hind-limb paralysis with cold limbs due to a clot
  • Discolored (bluish hue) foot pads or nailbeds (reduction in blood flow)
  • Collapse

Cats almost never pant or breath with their mouths open. It is important to know that a cat who is struggling to take in air or has trouble moving its rear legs may have advanced cardiac disease and must receive veterinary help immediately.


At VETMED, our board-certified cardiologist will perform a complete cardiovascular physical examination on your animal and discuss your pet’s medical history as it pertains specifically to the cardiovascular and pulmonary systems. Based on these initial findings, a diagnostic plan will be established and discussed with you. The following tests may also be performed for an accurate diagnosis.

  • Thoracic radiography
  • Electrocardiography
  • Echocardiography
  • Ancillary diagnostic tests
To schedule an appointment with Dr. Matt Miller or the VETMED Team, call 602.697.4694.

About the Author

Dr. Matt Miller, VETMED CardiologyMatthew Miller

DVM, MS, DACVIM – Cardiology Specialist at VETMED

Diplomate of the American College of Veterinary Internal Medicine – Cardiology

DVM, The Ohio State University
MS, The Ohio State University

Advanced Clinical Training:

  • Internship in Small Animal Medicine and Surgery at West Los Angeles Veterinary Medical Group
  • Residency in Small Animal Internal Medicine and Cardiology at The Ohio State University

Board Certifications:
Diplomate of the American College of Veterinary Internal Medicine – Cardiology (1988)
Clinical Interests:

  • Echocardiography
  • Interventional Catheterization
  • Management of Complex-Late Stage Heart Failure