Accessibility View Close toolbar

Heart Problems

image of a vet listening to a cat's heart.

A cat’s apricot-sized heart is susceptible to several problems. Some develop in young kittens while others may strike at any age.

Hypertrophic Cardiomyopathy

Cardiomyopathy results from a structural abnormality of the tissue around one or more of the heart’s chambers. It disrupts the heart’s normal blood pumping and collecting functions, which can lead to blood clots, respiratory distress and even death.

Some cases of cardiomyopathy are genetic. Others are unknown. Some other diseases, such as hyperthyroidism and high blood pressure, can also cause cardiomyopathy.

This disorder comes in several different types, the most common of which is hypertrophic cardiomyopathy (HCM). This thickening of the left ventricle’s muscle tissue is probably hereditary and most prevalent in male cats. The upper chambers enlarge and fill with blood, increasing lung pressure and causing shortness of breath. Blood clots may develop, sometimes making their way to the cat’s rear legs, where they produce sudden lameness and severe pain. Other symptoms include lethargy and open-mouthed or rapid breathing. HCM is relatively rare and requires immediate veterinary intervention. Medications may stabilize the patient.

Restricted Cardiomyopathy

Scar tissue buildup in the ventricle’s muscle causes restricted cardiomyopathy. This condition prevents the heart from relaxing, filling and emptying the way it normally should with each heartbeat.

Dilated Cardiomyopathy

This relatively rare form of cardiomyopathy involves a dilated, poorly contracting left ventricle. This decreases blood from the heart, which can lead to heart failure. Since researchers linked dilated cardiomyopathy to a lack of the amino acid taurine, manufacturers began adding it to cat food. Now veterinarians rarely see this disorder.

Congenital Heart Disorders

Ventrical Septal Defect

About 1 to 2 percent of kittens are born with congenital heart disorders. The most common is ventricular septal defect (VSD), which indicates a hole in the barrier between ventricles. If the hole is small and the pressure between the ventricles weak, the VSD is no big deal. However, a bigger hole can trigger conditions that range from exercise intolerance to congestive heart failure.

Patent Ductus Arteriosus

Patent ductus arteriosus is another congenital cardiac condition. With this disorder, a connection between the aorta and a major blood vessel fails to close after birth, as it does in a normal kitten. This causes excessive blood to flow from the kitten’s hearts to its lungs. If caught soon enough, there is a simple surgical fix.

Mitral Valve Dysplasia

Mitral valve dysplasia results from a poorly functioning mitral valve. The valve fails to regulate blood flow between the left atrium and ventricle. This blood backup causes vomiting, weight loss, exercise intolerance and, in some cases, blood clots.

All these congenital disorders are characterized by a swooshing sound in the heart. If a veterinarian hears this sound, he or she will assess the defect and devise the best course of action.

If your cat is struggling to breathe and/or has difficulty moving his or her hind legs, heart trouble may be the culprit. Call our office right away so we can help.


"Making the best years for your best friend"

Office Hours

Our Regular Schedule


8:00 am-4:00 pm


10:00 am-6:00 pm


1:00 pm-8:00 pm


10:00 am-6:00 pm


8:00 am-4:00 pm


9:00 am-2:00 pm




Feedback from our clients

  • "We have taken our furry friends to Dr. Nicoletti for a very long time. He is wonderful! Everyone there is great! Thanks for getting our newest furry in and taken care of. She came to us damaged and they helped us help her."
    Jennie Lewton Strubel
  • "Attila and Daisy say all 8 paws up for Dr Nicolleti, Anna and staff!!!"
    Nora Custer
  • "I couldn't take my animals any other place. Dr.Chico has so much love and compassion for not only my fur babies, but for me as their owner.. His charges are so reasonable, and his care for them is beyond words..
    I would like for them to give their birds names.. How about Bonnie and Clyde, or Frick and Frack..."
    Bert J Dinsio
  • "Dr. Nicoletti and the St. Kitts Veterinary Clinic staff are great people, kind and compassionate friends who love our pets as much as we do. Our cats -- and your pets -- will be in good hands if you need to visit St. Kitts."
    Robbie Lewis
  • "Dr. Nicoletti and the St. Kitts Veterinary Clinic staff are great people, kind and compassionate friends who love our pets as much as we do. Our cats -- and your pets -- will be in good hands if you need to visit St. Kitts."
    Robbie Lewis
  • "Dr. Nicolette was my vet for years. I trust him completely. He really cares about the animals under his care. My husband took our one dog to another vet once. That vet ran unnecessary test and ran the bill up double of what Dr. Nicolette charged me to treat the problem. We moved to Florida 3yrs ago and I still haven't found a vet I trust as much as Dr. Nicolette."
    Kassey Thomas