Feline Second-Degree AV Block (Mobitz II): Vet Guide 2025 🐱⚡🩺

Hello devoted cat parents! I’m Dr Duncan Houston BVSc 🩺. Today we'll explore second‑degree AV block, Mobitz Type II, a potentially serious arrhythmia. Learn causes, symptoms, ECG detection, treatment (including pacemakers), and caring support at home with clarity and empathy. 😊

🔍 What Is Mobitz Type II AV Block?

This form features sudden non-conducted P‑waves (dropped beats) without PR interval prolongation—where one or more atrial impulses fail to pass to the ventricles, causing bradycardia and intermittent skipped beats :contentReference[oaicite:2]{index=2}.

🧬 Who Gets It & Why?

• Often seen in older cats, especially with underlying heart disease :contentReference[oaicite:3]{index=3}.
• Linked to cardiomyopathy, AV-node degeneration, fibrosis, infection, neoplasia, trauma, metabolic issues, or drug effects (like digoxin) :contentReference[oaicite:4]{index=4}.

👂 Signs & Symptoms

• May be asymptomatic—or present with weakness, exercise intolerance, fainting, collapse, or congestive heart failure signs :contentReference[oaicite:5]{index=5}.
• Digoxin toxicity may cause GI upset—vomiting, poor appetite, diarrhea :contentReference[oaicite:6]{index=6}.

🔬 Diagnosing Mobitz II AV Block

• Physical exam: irregular soft or absent beats during dropped complexes.
• ECG: key test—static PR intervals with intermittent non-conducted P waves (e.g., 2:1, 3:1 ratios) :contentReference[oaicite:7]{index=7}.
• Holter monitor: detects intermittent block episodes :contentReference[oaicite:8]{index=8}.
• Diagnostics: bloodwork (CBC/chem/electrolytes), echo, chest X-ray, blood pressure, and underlying disease screening (thyroid, infection) :contentReference[oaicite:9]{index=9}.

🏥 Treatment & Management

1. Acute, Symptomatic Support

• Vagal tone reversal—trial of atropine or glycopyrrolate :contentReference[oaicite:10]{index=10}.
• Positive chronotropes—terbutaline, dobutamine, theophylline—help increase heart rate temporarily :contentReference[oaicite:11]{index=11}.
• Treat symptoms of CHF—oxygen, diuretics (furosemide), ACE inhibitors (benazepril) :contentReference[oaicite:12]{index=12}.

2. Definitive Therapy

• Pacemaker implantation is often recommended if symptomatic—prevents progression and sudden collapse :contentReference[oaicite:13]{index=13}.
• Even asymptomatic cats should be closely monitored—Mobitz II often progresses to complete block :contentReference[oaicite:14]{index=14}.

3. Treat Underlying Conditions

• Correct metabolic disturbances—electrolytes, hyperthyroidism, infections.
• Reduce/remove AV-nodal drugs (e.g., digoxin, calcium-blockers) :contentReference[oaicite:15]{index=15}.
• Manage cardiomyopathy or inflammatory disease.

📈 Prognosis & Monitoring

• Mobitz II can rapidly progress to high-grade or complete block—pacemaker greatly improves outcomes :contentReference[oaicite:16]{index=16}.
• Symptomatic cats have guarded prognosis without pacing.
• Follow-up every 3–6 months—ECG, echo, device checks if paced.

🏡 Home Care Tips

• Keep environment calm and stress-free 🧘‍♀️.
• Use **Ask A Vet app** 📱 for medication reminders and vet chats.
• Coziness matters—**Woopf & Purrz** beds help ease rest.
• Monitor for fainting, weakness, breathing difficulties—seek vet care at once.
• Maintain scheduled check-ups and tests—you’ll catch changes early.

📝 Key Takeaways

• Mobitz II AV block is a serious arrhythmia with dropped beats and fixed PR intervals.
• Typical signs: weakness, fainting, heart failure, GI upset if drug-related.
• Requires ECG/Holter and full diagnostic evaluation.
• Treatment options: pacing, drugs, underlying disease management.
• Proactive monitoring and home care boost safety and quality of life.

📞 When to Contact Ask A Vet

If your cat experiences fainting episodes, dizziness, sudden weakness, or breathing trouble—or is scheduled for anesthesia—reach out via the Ask A Vet app 💬. Early intervention can make a lifesaving difference.

✨ Final Thoughts

Feline Mobitz II AV block is uncommon but important. With diligent vet management—especially pacemaker use—and thoughtful home support, many cats live well. Ask A Vet, Woopf & Purrz can help you navigate every step of this journey 🐾❤️.