Benazepril (Lotensin) for Pets in 2025: Vet Guide to Heart Failure & Kidney Protein Loss 🐶🐱🫀

By Dr Duncan Houston, BVSc
Updated July 2025

💡 Benazepril (brand names Lotensin, Fortekor) is a long‑standing ACE inhibitor widely used to support pets with congestive heart failure (CHF), systemic hypertension, and protein‑losing kidney disease. It helps reduce vascular resistance, improves renal protection, and supports heart function when used properly.

🔬 Mechanism of Action & Pharmacology

• Drug class: ACE inhibitor — converts to active benazeprilat in the liver :contentReference[oaicite:1]{index=1}.
• Effect: Blocks production of angiotensin II → vessel dilation, lower afterload, reduced glomerular pressure.
• Excretion: Metabolized by liver; eliminated through bile and urine — ideal for pets with renal compromise :contentReference[oaicite:2]{index=2}.

📌 Primary Uses in 2025 Veterinary Care

• Congestive heart failure: Weak heart pumps better with lowered vascular resistance :contentReference[oaicite:3]{index=3}.
• Systemic hypertension: Especially in cats or dogs with kidney or heart disease :contentReference[oaicite:4]{index=4}.
• Proteinuria/protein-losing nephropathy (CKD): Reduces urinary protein loss and protects glomerular filtration :contentReference[oaicite:5]{index=5}.

⚙️ Dosage & Administration

• Tablets: 5, 10, 20, 40 mg — often compounded into liquid for precise dosing.
• Typically given once daily, up to 12‑hour dosing for continuous effect :contentReference[oaicite:6]{index=6}.
• Administer with or without food; giving with meals may reduce GI upset :contentReference[oaicite:7]{index=7}.
• If a dose is missed, give when remembered; do not double dose.

⚠️ Monitoring & Side Effects

• GI upset: Nausea, vomiting, diarrhea; food may help :contentReference[oaicite:8]{index=8}.
• Hypotension: Watch for lethargy after starting, especially if used with diuretics :contentReference[oaicite:9]{index=9}.
• Hyperkalemia: Monitor especially when on spironolactone or potassium supplements :contentReference[oaicite:10]{index=10}.
• Renal azotemia: Monitor BUN/creatinine periodically, especially when used with diuretics :contentReference[oaicite:11]{index=11}.
• Rare effects: Weakness, syncope, ataxia :contentReference[oaicite:12]{index=12}.

🔗 Drug Interactions to Watch For

• **Diuretics** (furosemide, spironolactone): May amplify blood pressure and kidney changes—monitor labs :contentReference[oaicite:13]{index=13}.
• **NSAIDs** (aspirin, Rimadyl): Can reduce benazepril effectiveness and increase acute kidney injury risk :contentReference[oaicite:14]{index=14}.
• **Potassium supplements or potassium-sparing diuretics:** Risk of elevated potassium :contentReference[oaicite:15]{index=15}.
• **Insulin/oral hypoglycemics:** May enhance glucose-lowering effects :contentReference[oaicite:16]{index=16}.
• **Antihypertensives:** Combined vasodilation effect—requires BP monitoring :contentReference[oaicite:17]{index=17}.

📋 Monitoring Recommendations

• Check blood pressure, BUN/creatinine, and electrolytes before starting and 3–7 days after dose changes :contentReference[oaicite:18]{index=18}.
• Recheck labs every 3–6 months or with clinical signs.
• Monitor for hypotension signs: weakness, dizziness, collapse.

📲 Ask A Vet App Support

The Ask A Vet app offers features to ensure safe long-term use:

• 📊 Reminders for lab monitoring and blood pressure checks
• ⚠️ Alerts for rapid weight loss, appetite changes, or GI signs
• 📋 Drug interaction checker—especially with NSAIDs, diuretics, and potassium supplements

➡️ Use Ask A Vet to support your vet’s benazepril protocol and ensure optimal outcomes. Visit AskAVet.com.

✅ Final Takeaways from Dr Duncan Houston

• Benazepril is a cornerstone drug in managing CHF, hypertension, and kidney disease in dogs and cats.
• Liver metabolism and dual elimination are ideal for renal-compromised pets.
• Requires regular lab monitoring and cautious pairing with diuretics and other meds.
• Never combine with NSAIDs without vet approval.
• Help your pet thrive with structured use, monitoring, and Ask A Vet support.

🫀🐾 With vet-guided benazepril support, your pet can enjoy better heart and kidney health in 2025 and beyond.