Heart Disease in Cats

Laurie Anne Walden, DVM

Image by VBlock on Pixabay

Cats with heart disease often don’t show any signs of illness. Sometimes the very first sign that a cat has heart disease is a sudden life-threatening condition like arterial thromboembolism (blood clot) or even sudden death. These are some other signs that a cat might have heart trouble:

• Increased sleeping respiratory rate (breaths per minute counted while the cat is asleep)
• Labored breathing or open-mouth breathing
• Coughing
• Rear leg weakness
• Sudden inability to use one or more legs (a medical emergency in a cat)

 
Different terms are used to describe the severity of heart problems. Heart disease means that something about the heart is not normal, but the heart is still pumping blood as it should. Heart failure means that the heart disease has gotten worse and the heart is no longer pumping blood normally. Congestive heart failure is a more severe form of heart failure in which fluid builds up in the lungs.
 
The best way to diagnose and stage heart disease is with echocardiography (ultrasound of the heart) by a veterinary cardiologist. Chest radiographs are used to measure the size of the heart and detect fluid in the lungs. Blood tests are sometimes used to screen cats for evidence of heart failure.
 
Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy is the most common heart disease in cats. The disease can affect cats of any breed, but it has a known genetic link in Maine coon cats and Ragdolls. In this disease, the heart walls become thickened and stiff and can’t pump blood effectively. The disease eventually causes congestive heart failure. Treatment depends on the cat’s stage of heart disease.
 
Cats with hypertrophic cardiomyopathy are at risk of arterial thromboembolism, a painful condition in which a blood clot blocks blood supply to one or more legs. Cats with arterial thromboembolism are often euthanized because of the guarded to poor prognosis. Their best chance of survival is hospitalization at a 24-hour facility that can provide specialized care.
 
Restrictive Cardiomyopathy
Restrictive cardiomyopathy is caused by scar tissue in the heart muscle. The cause is not known. The scar tissue prevents the heart muscle from contracting normally, affecting its ability to pump blood.
 
Dilated Cardiomyopathy
Dilated cardiomyopathy used to be more common in cats than it is now. In cats, this condition is caused by low levels of taurine (an amino acid) in the diet. Commercial cat foods are now required to contain a minimum level of taurine, so dilated cardiomyopathy has become rare in cats. Cats that eat homemade or vegetarian diets might not be getting enough taurine, in which case they are at risk of developing dilated cardiomyopathy.
 
Dilated cardiomyopathy causes the heart walls to become thinner and weaker. The heart enlarges, and the weak heart walls can’t pump blood normally.
 
Congenital Heart Disorders
Congenital heart disorders are present at the time of birth. The most common type in cats is ventricular septal defect, which is a hole between the lower chambers of the heart. Some kittens with a congenital heart disorder lead normal lives; others are severely affected. Treatment might be medical or surgical, depending on the type and severity of the disorder.
 
More Information
See the HeartSmart website (Tufts University School of Veterinary Medicine) to find out more about heart diseases in cats and dogs: https://vet.tufts.edu/foster-hospital-small-animals/specialty-services/cardiology/heartsmart
 
Image source: https://pixabay.com/photos/maine-coon-cat-pet-animal-feline-7222631/

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