Veterinary 2025 Guide: Itraconazole (Itrafungol®) Use in Dogs & Cats 🐾🩺

Hello, I’m Dr Duncan Houston BVSc. In this comprehensive 2025 guide, we review the safe and effective use of itraconazole—including oral Itrafungol®—for treating fungal infections in dogs and cats. We’ll cover pharmacology, clinical uses, dosing, monitoring, side effects, drug interactions, and safety best practices enhanced by Ask A Vet insights 😊.

🔎 1. What Is Itraconazole?

Itraconazole is a triazole antifungal (brands: Itrafungol®, Sporanox®), used systemically in pets—capsule, tablet, or oral liquid—to treat dermatophytosis, aspergillosis, blastomycosis, cryptococcosis, and other fungal infections :contentReference[oaicite:3]{index=3}.

⚙️ 2. Mechanism of Action

It inhibits fungal cytochrome P450 enzymes needed for ergosterol production—essential to fungal cell membranes—thus arresting fungal growth :contentReference[oaicite:4]{index=4}.

💊 3. Species & Uses

• Cats: FDA‐approved Itrafungol® for ringworm (Microsporum canis), often used off‑label for cryptococcosis, aspergillosis, blastomycosis :contentReference[oaicite:5]{index=5}.
• Dogs: Off‑label use for systemic and dermatologic fungal diseases—blasto, valley fever, dermatophytes :contentReference[oaicite:6]{index=6}.

📏 4. Dosing & Administration

• ***Cats (Itrafungol®):*** 5 mg/kg once daily, one week on/one week off, for 3 cycles (ringworm protocol) :contentReference[oaicite:7]{index=7}.
• ***Dogs:*** 5–10 mg/kg daily, given whole or split, depending on infection severity :contentReference[oaicite:8]{index=8}.
• Capsules/tablets should be given with a high‑fat meal to improve absorption; oral solution is dosed on empty stomach :contentReference[oaicite:9]{index=9}.
• Avoid compounding except by trusted compounding pharmacies—bioavailability can drop significantly :contentReference[oaicite:10]{index=10}.

⚠️ 5. Adverse Effects & Safety Monitoring

• Common GI signs: anorexia, vomiting, diarrhea, drooling, weight loss, lethargy—dose-dependent :contentReference[oaicite:11]{index=11}.
• Liver toxicity warning: monitor ALT/ALKP before and every 4–6 weeks during treatment :contentReference[oaicite:12]{index=12}.
• Rare dermatologic signs: skin ulcers, swelling of limbs :contentReference[oaicite:13]{index=13}.

📋 6. Drug Interactions

Itraconazole is a strong CYP450 inhibitor. Use caution with:
antacids, H2 blockers, corticosteroids, benzodiazepines, CCBs, cisapride, cyclosporine, digoxin, ivermectin, methadone, phenobarbital, macrolides, NSAIDs—discuss all medications with clients :contentReference[oaicite:14]{index=14}.

🔄 7. Missed Dose & Overdose Handling

Give missed dose when remembered, unless near next scheduled dose—never double up :contentReference[oaicite:15]{index=15}. In overdose—symptoms include vomiting, drooling, anorexia, liver effects—seek emergency care or call poison control :contentReference[oaicite:16]{index=16}.

📦 8. Storage & Client Handling Advice

• Store capsules 59–77 °F; oral solution 68–79 °F; protect from moisture/light :contentReference[oaicite:17]{index=17}.
• Clients should wear gloves when handling Itrafungol®; wash hands after administering solution :contentReference[oaicite:18]{index=18}.

🩺 9. Client Education & Monitoring

• Explain that full treatment—even beyond symptom resolution—is critical to prevent relapse.
• Encourage routine bloodwork (especially liver enzymes every 4–6 weeks).
• Use Ask A Vet app for dosing reminders, handling instructions, and alert notifications for owners.
• Plan follow-up exams every 4–6 weeks or with symptom changes.

💡 10. Alternatives & Adjunct Therapies

• Consider terbinafine, fluconazole, or ketoconazole based on pathogen and tolerance.
• Topical antifungals (lime sulfur dips, shampoo) for ringworm support.
• Environmental decontamination in dermatophytosis cases (cleaning surfaces, bedding).

✔️ 11. Key Takeaways

• Itraconazole (Itrafungol®) is a safe and effective antifungal for dogs/cats with proper dosing.
• Ensure administration with or without food depending on formulation.
• Monitor GI signs and liver values regularly.
• Manage drug interactions carefully.
• Support clients using Ask A Vet app for better compliance and outcomes.

At Ask A Vet, we equip vets and owners with treatment trackers, dosing reminders, and expert support. Download our app to ensure safe antifungal therapy, real-time vet access, and optimal pet care ❤️