Feline Digoxin Toxicity: Vet Guide 2025 🐱⚠️💊

Hello devoted cat caregivers! I’m Dr Duncan Houston BVSc 🩺. Digoxin is sometimes used in cats for heart failure or arrhythmias—but it carries a narrow therapeutic window and overdosing can be serious. In this article you’ll learn the causes, symptoms, ECG features, diagnostics, treatments, prognosis, and home care with caring emoji flair! 😊

🔍 What Is Digoxin & Why Toxicity Occurs

Digoxin is a cardiac glycoside that strengthens heart contractions and slows conduction through the AV node :contentReference[oaicite:4]{index=4}. Toxicity occurs when blood levels exceed the therapeutic range (~0.5–2 ng/mL) due to overdose, altered metabolism, electrolyte imbalances, or drug interactions :contentReference[oaicite:5]{index=5}.

⚠️ Who's at Risk?

• Any cat on digoxin—but especially older cats, kidney or heart disease cases :contentReference[oaicite:6]{index=6}.
• Low potassium or magnesium, high calcium increase sensitivity :contentReference[oaicite:7]{index=7}.
• Drug interactions or manufacturer variability (tablets vs elixir) can affect blood levels :contentReference[oaicite:8]{index=8}.

👀 Warning Signs to Watch For

Signs may be chronic or acute:

• 💓 Cardiac – irregular pulse, slow or fast heartbeats, AV blocks, PVCs, VT :contentReference[oaicite:9]{index=9}.
• 🍽️ GI – anorexia, vomiting, diarrhea, drooling :contentReference[oaicite:10]{index=10}.
• 😵 CNS – lethargy, weakness, confusion, seizures (rare) :contentReference[oaicite:11]{index=11}.
• 👁️ Visual changes (in humans—cats may show subtle sensory changes) :contentReference[oaicite:12]{index=12}.
• 🫁 Worsening heart failure signs—coughing, breathing difficulty, collapse :contentReference[oaicite:13]{index=13}.

📊 ECG & Diagnostic Findings

• Digoxin effect: 'scooped' ST depression (“reverse‑tick” or Salvador Dalí’s moustache), flattened/inverted/biphasic T waves, short QT :contentReference[oaicite:14]{index=14}.
• Toxic ECG changes: AV blocks, bradycardia, PVCs, ventricular tachycardia, bidirectional VT—nearly pathognomonic :contentReference[oaicite:15]{index=15}.
• Blood tests: check digoxin levels 8–10 hrs post-dose, plus electrolytes (K⁺, Mg²⁺, Ca²⁺), kidney and liver values :contentReference[oaicite:16]{index=16}.

🏥 Emergency & Veterinary Treatment

1. Stop Digoxin Immediately

• Discontinue for ≥48 hrs until blood and signs normalize :contentReference[oaicite:17]{index=17}.

2. Hospital Supportive Care

• Cardiac monitoring, IV fluids, oxygen, GI support :contentReference[oaicite:18]{index=18}.
• Correct low potassium or magnesium to stabilize the heart :contentReference[oaicite:19]{index=19}.

3. Treat Arrhythmias

• Atropine for bradycardia or AV block :contentReference[oaicite:20]{index=20}.
• Magnesium for PVCs/VT; temporary pacing if necessary :contentReference[oaicite:21]{index=21}.
• Lidocaine or phenytoin in severe ventricular arrhythmias :contentReference[oaicite:22]{index=22}.

4. Antidote (Antibody Fragments)

Digoxin‑specific antibody fragments (Digibind/DigiFab) bind and neutralize drug. Used in life-threatening toxicity :contentReference[oaicite:23]{index=23}.

5. GI Decontamination (in acute ingestion)

• Activated charcoal or cholestyramine within 2 hours of ingestion :contentReference[oaicite:24]{index=24}.

📈 Prognosis & Monitoring

• Early treatment and electrolyte correction lead to good recovery; serious arrhythmias carry risk :contentReference[oaicite:25]{index=25}.
• Recheck digoxin levels, ECG, electrolytes regularly upon restarting medication :contentReference[oaicite:26]{index=26}.
• Adjust future dose carefully and monitor closely :contentReference[oaicite:27]{index=27}.

🏡 Home Care & Prevention

• Use the **Ask A Vet app** 📱 for reminders, symptom logging, and after-care advice.
• Feed consistent diet and schedule meds exactly—never use human digoxin formulations :contentReference[oaicite:28]{index=28}.
• Track appetite, vomiting, breathing rate, activity, and ECG-related signs.
• Keep follow-up appointments to check blood levels and ECG.
• Ensure calm, cozy environment—**Woopf & Purrz** bedding promotes rest 🛏️.

📝 Key Takeaways

• Digoxin is effective but carries a narrow margin—monitor blood and watch electrolytes closely.
• Signs include GI upset, arrhythmias, breathing changes, and lethargy.
• Look for ECG 'reverse‑tick' and arrhythmias; confirm with blood levels.
• Treatment includes stopping drug, hospital care, electrolyte correction, antidote if needed.
• Careful reintroduction of digoxin and ongoing monitoring ensures safety.

📞 When to Contact Ask A Vet

If your cat behaves oddly, vomits, eats less, collapses, breathes fast, or pulse feels irregular—use the **Ask A Vet app** 💬 immediately for expert support!

✨ Final Thoughts

Digoxin toxicity in cats is serious—but with prompt veterinary care, targeted treatment, and attentive home support, recovery is achievable. You're not alone—Ask A Vet, Woopf & Purrz, and expert guidance are with you every step! ❤️🐾