Your cat’s heart pumps fresh blood and oxygen throughout her body. Proper function of this vital organ ensures that all cells and tissues receive enough oxygen and maintain metabolism. If the heart begins to fail, the effects can be significant and potentially life-threatening. Understanding the types and signs of cardiac disease can help you recognize illness in your cat before it advances.


Signs of heart disease

Heart disease can be a silent threat to any pet, and, because cats are notorious for hiding signs of illness, it’s important to be particularly observant for changes in behavior, appetite, and activity level. If your cat displays any of the following signs, call our office right away:

  • Vomiting
  • Coughing
  • Lethargy
  • Decreased appetite
  • Weakness
  • Pale or blue-tinged gums
  • Swollen abdomen
  • Collapsing or fainting
  • Rear limb paralysis

Hypertrophic cardiomyopathy

The most common type of heart disease to affect cats is hypertrophic cardiomyopathy (HCM), which causes the muscular wall of the heart chambers to become thicker than normal. Since the growth occurs inward, the heart’s chambers—particularly the left ventricle—become smaller. The smaller ventricle cannot accommodate a normal volume of blood, causing less blood to be pumped out to the body’s tissues.


Congestive heart failure

Any condition—including hypertrophic cardiomyopathy—that interferes with the heart’s ability to pump efficiently and keep up with blood flow can cause secondary congestive heart failure to develop. When blood is pumped at an abnormally slow rate, it begins to back up in the vessels of the lungs. Increased pressure within pulmonary vessels causes fluid to leak out of them into lung tissue, which leads to congestive heart failure. The buildup of fluid within the lungs causes difficulty breathing and can interfere with the diffusion of oxygen into the blood.


Aortic thromboembolism

Another consequence of hypertrophic cardiomyopathy is the formation of a blood clot within one of the heart’s chambers. Blood clots can break free and travel through the largest artery in the body—the aorta—as it courses through the thoracic cavity and abdomen. As the aorta narrows into the arteries that take blood to the back legs, the clot gets stuck, blocking blood flow. Cutting off blood flow to the back legs deprives them of oxygen, quickly leading to tissue death.

Aortic thromboembolism causes sudden paralysis of the cat’s rear legs. Affected cats are often found by their owners dragging the back legs and in intense pain. Since treatment is seldom successful, cats that develop this complication of heart disease are typically euthanized.


Heartworm disease

Although many people think that only dogs can contract heartworm disease, cats can also be affected. Passed by the bite of a mosquito, microscopic larval heartworms develop into large adult worms in the heart and blood vessels of the lungs. The cat is not a natural host for heartworms, so the worms cannot reproduce and multiply into a large population (like they do in dogs). But, heartworm disease is still a serious threat to cats. The presence of even a few worms can cause significant inflammation and damage to the lungs.

There is no approved medication to kill heartworms in cats, so treatment is geared toward reducing inflammation and lessening the tissue damage caused by the worms while they are alive. Because there is no cure, the best treatment is prevention. If your cat is not currently on a regular heartworm preventive medication, call us to schedule an appointment so she can be protected.

Dilated cardiomyopathy

Taurine is an essential amino acid that must be included in every cat’s diet. Without it, the heart muscle becomes weak and cats can develop dilated cardiomyopathy (DCM). The pressure of blood being pumped through the heart causes the weakened heart walls to become thinner and the heart chambers to become dilated over time. The weak heart walls do not contract with enough force to pump a sufficient amount of blood through the body, leading to congestive heart failure and decreased blood flow to the tissues.

Commercially manufactured cat foods contain adequate amounts of taurine for proper heart function. However, if your cat is fed table scraps or a homemade diet, she is at great risk for development of this fatal heart disease. You should never attempt to feed your cat a homemade diet unless it has been specifically prescribed by a veterinarian and formulated to contain all of the important nutrients cats need.


Questions about feline heart disease? Is your cat not acting like herself? Call us at 916-726-2334.