Feline Heart Murmurs: Vet Guide 2025 🐱🩺🔍

Hello cat guardians! I’m Dr Duncan Houston BVSc 🩺. Hearing a “whoosh” or “swoosh” during your cat’s check-up can be worrying—but not all murmurs are harmful. This guide explains the difference between harmless (innocent) and pathological murmurs, what they mean, how we diagnose and treat them, and how you can support your feline friend at home with love and care 😊.

🔍 What Is a Heart Murmur?

A heart murmur is an abnormal “whooshing” sound heard auscultating with a stethoscope—it’s caused by turbulent blood flow, either within the heart or nearby vessels :contentReference[oaicite:2]{index=2}. Importantly, a murmur is a sign, not a diagnosis: some cats have no disease, while others may have significant underlying heart issues :contentReference[oaicite:3]{index=3}.

🧬 Innocent vs. Pathologic Murmurs

• Innocent (physiologic) murmurs: Common in kittens or during stress, typically low-grade and temporary, posing no health risk :contentReference[oaicite:4]{index=4}.
• Pathologic murmurs: Indicate structural heart disease—valve leaks, congenital defects (e.g., VSD, PDA), cardiomyopathy, anemia, hyperthyroidism, or hypertension :contentReference[oaicite:5]{index=5}.

🎛️ Grading Murmurs (I–VI)

Murmurs are graded from I (very quiet) to VI (extremely loud). However, loudness doesn’t always match severity—a soft murmur might conceal serious disease, and a loud one could be benign :contentReference[oaicite:6]{index=6}.

📋 Common Causes of Murmurs in Cats

• Congenital defects: VSD, PDA, valve dysplasia
• Cardiomyopathies: hypertrophic (HCM), dilated, restrictive
• Systemic diseases: anemia, hyperthyroidism, hypertension, infection
• Stress or transient conditions: fever, excitement :contentReference[oaicite:7]{index=7}.

🛠️ How We Diagnose Murmurs

• Stethoscope exam: note murmur timing (systolic/diastolic), grade, and location
• Bloodwork & blood pressure: rule out anemia, thyroid or kidney problems :contentReference[oaicite:8]{index=8}.
• Chest X-ray: assess heart size and fluid in lungs :contentReference[oaicite:9]{index=9}.
• ECG/Holter: detect arrhythmias or chamber enlargement :contentReference[oaicite:10]{index=10}.
• Echocardiogram (echo): gold standard—provides images of heart structure and blood flow via Doppler to locate turbulent areas :contentReference[oaicite:11]{index=11}.
• NT‑proBNP & cardiac biomarkers: help detect occult heart disease :contentReference[oaicite:12]{index=12}.

🫀 What Echo Can Show Us

An echo with Doppler can identify thickened muscle (HCM), chamber enlargement, valve regurgitation, septal defects, and pulmonary pressure abnormalities— making it essential to distinguish innocent from pathologic murmurs :contentReference[oaicite:13]{index=13}.

⚕️ Treatment Options

1. Innocent Murmurs

• No treatment—just regular monitoring.

2. Pathologic Causes

• Congenital defects: Some may need surgical correction (e.g., ductal ligation).
• HCM / cardiomyopathy: Manage with beta-blockers, ACE inhibitors, pimobendan, clot prevention (clopidogrel) :contentReference[oaicite:14]{index=14}.
• Systemic disease: Treat underlying cause (e.g., chelation for anemia, methimazole for hyperthyroidism) :contentReference[oaicite:15]{index=15}.

📈 Prognosis & Monitoring

• Innocent murmurs often disappear by 4–5 months in kittens :contentReference[oaicite:16]{index=16}.
• Prognosis in pathologic murmurs depends on diagnosis—early treatment can extend quality life; CHF air expect 6–18 months survival :contentReference[oaicite:17]{index=17}.
• Recheck with echo, ECG, and labs periodically—every 6–12 months if no treatment needed, more frequently if on meds.

🏡 Supportive Home Care Tips

• Use the **Ask A Vet app** 📱 to log resting breathing rate (>30/min signals trouble), appetite, exercise, and med reminders.
• Provide calm, warm beds like **Woopf & Purrz** to reduce stress 🛏️.
• Keep consistent diet, water access, and avoid high-sodium foods.
• Know emergency signs: rapid breathing, collapse, blue/pale gums, hind-limb pain—seek urgent vet care.

📝 Key Takeaways

• A heart murmur is a sound, not a diagnosis—it can be harmless or signal significant disease.
• Diagnosis depends on echo, ECG, X-ray, blood tests, and blood pressure.
• Treatment varies with cause: monitoring, meds, surgery, or managing underlying disease.
• Home monitoring and low-stress lifestyle improve outcomes.

📞 When to Contact Ask A Vet

If your cat shows sudden breathing trouble, collapse, poor appetite, or lethargy—reach out via **Ask A Vet app** 💬 for fast, expert advice.

✨ Final Thoughts

Heart murmurs in cats aren't always scary—but they should never be ignored. With timely veterinary evaluation, targeted treatment, and nurturing care, many cats live long, happy lives. And with tools like Ask A Vet, Woopf & Purrz by your side, you’re supporting every heartbeat. ❤️🐾