Hypertrophic Cardiomyopathy in Cats: Diagnosis, Treatment Options, and How to know when it’s time for Euthanasia

Hypertrophic cardiomyopathy (HCM) is a diseases that causes the heart muscle to thicken reducing the ability to pump blood. It can lead to congestive heart failure, arrhythmias, and blood clots and can occur in cats at any age. It often goes undiagnosed until it is very advanced as many cats with this disease are completely healthy until symptoms arise. While treatment can help prolong life, there often comes a point where euthanasia becomes the most compassionate choice. In this guide, we’ll discuss what HCM is, the available treatment options, and how to determine when it may be time to say goodbye to your beloved cat.

Symptoms of HCM

Many cats with HCM do not show symptoms until the disease has advanced. In some cats, a heart murmur can be detected by your veterinarian before the disease has advanced, and your veterinarian may send your cat for an echocardiogram to make the diagnosis. Symptoms of HCM include:

• Increased respiratory rate or difficulty breathing
• Lethargy and reduced activity levels
• Fainting or collapsing
• Sudden paralysis in the hind legs (a sign of aortic thromboembolism, or ATE)
• Open-mouth breathing or excessive panting
• Occasionally weight loss and vomiting (this is less common)

Treatment Options for HCM

While HCM is a progressive disease and there is no cure, medical intervention can help manage symptoms and slow progression. Treatment typically includes:

Medications

• Beta-blockers (e.g., atenolol): Help slow heart rate and reduce the heart’s workload.
• Calcium channel blockers (e.g., diltiazem): Improve heart muscle relaxation and function.
• Diuretics (e.g., furosemide): Reduce fluid buildup in the lungs and chest.
• Anticoagulants (e.g., clopidogrel or aspirin): Help prevent blood clots.

Dietary and Lifestyle Adjustments

• Reducing stress and maintaining a calm environment can help prevent episodes of distress.
• A low-sodium diet may be recommended to minimize fluid retention.
• Regular veterinary monitoring is necessary to adjust treatment as the disease progresses.

Despite treatment, HCM is a progressive disease, and many cats eventually reach a stage where their quality of life is significantly compromised.

Knowing When It’s Time for Euthanasia

Deciding when to euthanize a pet is never easy, but with HCM, there are key indicators that can help guide you. One goal is to ensure your cat is not suffering and has a good quality of life for as long as possible. Another goal of many clients is to be able to say goodbye at home while their beloved friend is peaceful rather than having to rush them to the emergency room for euthanasia.

Signs That Indicate a Decline in Quality of Life

1. Repeated episodes of respiratory distress – If your cat has to be rushed to the hospital repeatedly for difficulties breathing, it may be time to consider euthanasia. Often for the first, or even second episode it is reasonable to try to hospitalize and treat a cat, but cats in particular really hate being at the hospital, so if hospitalization is becoming frequent, euthanasia may be the kindest decision. Repeated hospitalization is not only stressful for cats, but it can also quickly become cost prohibitive for pet parents.
2. Aortic Thromboembolism (ATE) Episodes – If your cat experiences a sudden loss of mobility in the hind legs due to a clot, the pain and distress can be severe. Many pet parents choose to euthanize their cat when this happens because many cats will never recover and the likelihood of recurrence is extremely high.
3. Frequent Collapses or Fainting Episodes – These are often signs of worsening heart function and can indicate sudden cardiac arrest is imminent.
4. General decrease in quality of life – If your cat is lethargic all the time, hiding often, losing weight, losing interest in food or attention they may be telling you they are suffering more than they are enjoying life.
5. Lack of Response to Medication – If treatments no longer improve breathing, circulation, or general comfort, the disease may have reached its final stages.
6. Owner factors – if you are starting to get concerned that you can’t leave your cat alone for more than a few hours or something terrible might happen, or if you are worried you may have to rush your cat to the hospital for euthanasia and would prefer them to pass peacefully at home, it may be time to consider euthanasia.

Conclusion

Hypertrophic cardiomyopathy is a heartbreaking disease. While treatments sometimes can extend a cat’s life and improve their well-being, there comes a time when letting go is the kindest choice. By recognizing the signs of decline and prioritizing your cat’s comfort, you can ensure that their final moments are filled with love and peace. Remember, choosing euthanasia is never about giving up—it’s about preventing unnecessary suffering and honoring the life you shared together.

If you would like more guidance and support, schedule a 45 minute teleconsult with one of our compassionate veterinarians who can review your pet’s medical records and history and help you formulate the most compassionate and loving plan for your family.