Diagnosing and Treating Heart Disease in Cats: Tests, Medications, and Care

Heart disease in cats can be hard to detect because many cats may not show signs until the condition is advanced, making regular checkups with your veterinarian essential. If diagnosed, treatment depends on the type and stage of heart disease, and your veterinarian will guide you with medications, diet, or monitoring to help your cat with heart disease live a comfortable life.

How Heart Disease in Cats Is Diagnosed^1-3

Diagnosing heart disease in cats can be challenging, especially since many cats show no obvious signs in the early stages. However, veterinarians use a combination of exams, blood tests, imaging, and specialized tools to detect heart problems as early as possible.

Veterinary Exam^4-6

Your veterinarian will start with a physical exam and listen to your cat’s heart and lungs. They may hear a murmur, irregular heartbeat, or lung sounds suggesting fluid buildup. In cats, unlike dogs, a heart murmur does not always mean heart disease. Some cats with heart disease have no murmur, while many with a soft murmur do not have heart muscle problems.

Other signs may include cold or pale paws, labored breathing, or low body temperature. In some cases, especially with blood clots, cats may show sudden weakness or pain in the back legs.

Blood and Lab Testing

Several blood tests may help uncover causes or complications of heart disease:

• Complete blood count (CBC), chemistry panel, and urinalysis (UA) provide a general overview of your cat’s health.
• T4 (thyroid test) helps detect hyperthyroidism, a common condition in older cats that can cause heart changes.
• NT-proBNP is a blood test that may help distinguish between heart disease and respiratory illness if a full heart ultrasound is not available.
• Troponin I (cTnI) measures heart muscle damage and may be used to assess risk.
• Taurine testing, in rare cases, checks for deficiency-related heart disease.

Other Tests

Your cat’s veterinarian or veterinary specialist may recommend further testing, including:

• Blood pressure measurement. High blood pressure (hypertension) can cause thickening of the heart muscle and may be present alongside heart disease. Blood pressure checks are often part of a complete heart workup.
• Chest x-rays. X-rays (radiographs) can show an enlarged heart in cats or fluid around the lungs, which may indicate heart failure. However, early heart disease might not be visible, and the heart can appear normal even in some cases of heart failure.  
• Point-of-care (POC) ultrasound. This quick ultrasound is often used in emergency situations to check for fluid around the lungs or heart.
• Electrocardiogram (ECG). An ECG records your cat’s heart rhythm and helps detect abnormal heartbeats (arrhythmias).
• Echocardiography (heart ultrasound). This is the gold standard for diagnosing heart disease in cats, which means it is the best way to diagnose whether your cat has heart disease. An echocardiogram gives a detailed picture of the heart’s size, shape, motion, and function. Typically, it is performed by a veterinary cardiologist or trained specialist. In some cases, your veterinarian may recommend it as a screening tool in breeding cats from high-risk breeds.  
• Genetic testing. Genetic testing may help identify heart disease risk in breeds like Maine Coons, Ragdolls, and Sphynx cats. However, a negative test does not rule out heart disease, so regular veterinary checkups and heart monitoring are still important.³

Treatment of Cat Heart Disease

Cat heart disease treatment depends on the type and stage of the condition. Some cats, especially those in early stages, may not need medication. In these cases, your veterinarian may recommend regular checkups and monitoring to track any changes.

Feline Heart Disease Medications

Cats with severe congestive heart failure need emergency treatment right away. This may include staying in the veterinary hospital for oxygen therapy, medications to remove fluid (diuretics), and procedures to drain fluid from the chest (thoracocentesis). Cats with a large amount of chest fluid often feel much better after the fluid is removed.

Medications that might be recommended by your veterinarian, especially for congestive heart failure in cats, may include³:

• Antiarrhythmic agents like beta blockers (atenolol) or calcium channel blockers (diltiazem) to manage heart rate  
• Diuretics (furosemide) to remove excess fluid if heart failure is present  
• ACE inhibitors (like enalapril) to lower blood pressure and reduce heart strain
• Anticoagulants or antiplatelet medications (like clopidogrel) to reduce the risk of blood clots

You may be wondering, “Are cats with heart disease in pain?” Cats with arterial thromboembolism (ATE) often experience significant pain, especially in the first couple of days. Managing this pain is very important. Veterinarians will commonly hospitalize these patients and use medications like fentanyl or buprenorphine to help keep the cat comfortable during recovery. Your veterinarian will choose the most appropriate pain relief based on your cat’s condition and need.² Anticoagulants or antiplatelet medications (like clopidogrel) will be used to reduce the risk of blood clots.³ Outside of painful complications like ATE, most cats with well-managed heart disease do not show signs of pain.

Other medications to treat heart disease in cats include:

• Thyroid medication if heart disease is caused by hyperthyroidism.
• Felycin®-CA 1 (sirolimus). The US Food and Drug Administration (FDA) recently granted conditional approval for the first medication approved to help manage heart muscle thickening in cats with subclinical HCM. Your veterinarian may recommend this medication depending on your cat’s condition.

The Role of Nutrition in Feline Heart Disease²

Nutrition plays an important role in managing heart disease. Your veterinarian may assess your cat’s diet by asking:

• Is the food supporting heart health? Ensuring adequate taurine and protein is important, and increased omega-3 fatty acids (EPA/DHA) may also be beneficial. Depending on the stage of heart disease, avoiding diets high in sodium is often encouraged. Your veterinarian may recommend a diet with nutrients like taurine and antioxidants.
• What else is your cat eating? Treats, table food, and supplements should be included in the plan.
• Will your cat eat it? Taste and texture matter; choosing a preferred food helps long-term success.
• What works for you? Your veterinarian will consider your ability to manage feeding and medications.

Heart Health for Cats: Proactive Care

Supporting your cat’s heart health starts with regular veterinary checkups, especially for senior or at-risk breeds. Prevention of heartworm disease in cats is essential, even for indoor cats. Feeding a heart-healthy diet with nutrients like taurine and omega-3 fatty acids, reducing household stress, and watching for changes like rapid breathing or appetite loss are also important steps.

While life expectancy for cats with heart disease depends on the type, stage, and severity of disease, ongoing care can help improve quality of life and longevity. Some conditions, like heart disease caused by taurine deficiency or hyperthyroidism, may even improve with proper treatment. Talk to your veterinarian to better understand your cat’s condition, expected disease progression, and prognosis.

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For more expert tips on cat health, explore our other cat symptom articles.

References

1. Kittleson MD, Côté E. The Feline Cardiomyopathies: 1. General concepts. J Feline Med Surg. 2021;23(11):1009–1027.

2. Tilley LP, Smith FWK, Sleeper MM, Kraus MS. Manual of Canine and Feline Cardiology [e-book]. 6th ed. Elsevier; 2025.

3. Kittleson MD, Côté E. The feline cardiomyopathies: 2. Hypertrophic cardiomyopathy. J Feline Med Surg. 2021;23(11):1028–1051.

4. Fuentes VL, Abbott J, Chetboul V, et al. ACVIM consensus statement guidelines for the classification, diagnosis, and management of cardiomyopathies in cats. J Vet Intern Med. 2020;34(3):1062–1077.

5. Payne JR, Brodbelt DC, Fuentes VL. Cardiomyopathy prevalence in 780 apparently healthy cats in rehoming centres (the CatScan study). J Vet Cardiol. 2015;17:S244–S257.

6. Paige CF, Abbott JA, Elvinger F, Pyle RL. Prevalence of cardiomyopathy in apparently healthy cats. JAVMA. 2009;234(11):1398–1403.