Veterinary 2025 Guide: Ponazuril for Protozoal Infections in Pets 🐾🩺

Hello, I’m Dr Duncan Houston BVSc. This 2025 guide covers Ponazuril—a triazine-based antiprotozoal used off-label in dogs and cats to treat intestinal coccidia, Neospora, Toxoplasma, and other protozoal pathogens. You'll find pharmacology, dosing, side effects, precautions, and client support integrated with Ask A Vet 😊.

🔍 1. What Is Ponazuril?

Ponazuril (trade name Marquis®) is an oral antiprotozoal paste officially approved for equine protozoal myeloencephalitis in horses. It’s used extra-label in small animals for coccidiosis and systemic protozoal infections :contentReference[oaicite:3]{index=3}.

It inhibits protozoal DNA synthesis by blocking key enzymes and pyrimidine formation pathways :contentReference[oaicite:4]{index=4}.

🎯 2. Indications in Pets

• Coccidiosis: Causes diarrhea in puppies/kittens; ponazuril is effective against Isospora spp. :contentReference[oaicite:5]{index=5}.
• Neospora/Toxoplasma: Off-label use for neurologic disease in dogs & cats; prescribed courses up to 90 days :contentReference[oaicite:6]{index=6}.

💊 3. Dosing & Administration

• For coccidiosis: 20–50 mg/kg PO once daily for 2–5 days (typical shelter dose: 30–50 mg/kg) :contentReference[oaicite:7]{index=7}.
• For systemic protozoal infections: 7.5–15 mg/kg daily for up to 28–90 days :contentReference[oaicite:8]{index=8}.
• Administer as paste or compounded suspension, with or without food; if vomiting, give with food :contentReference[oaicite:9]{index=9}.
• If a dose is missed, give when remembered unless near next dose—don’t double-dip.

⚠️ 4. Side Effects & Risks

• Common GI upset: diarrhea, vomiting, mild lethargy—usually mild :contentReference[oaicite:10]{index=10}.
• Dry eye (keratoconjunctivitis sicca) reported in predisposed dogs :contentReference[oaicite:11]{index=11}.
• Serious adverse events: mouth/nose blisters, skin rash, seizures—stop and vet if these appear :contentReference[oaicite:12]{index=12}.
• High overdose levels (e.g., 50 mg/kg for 10 days) linked to anorexia, weight loss, mild colic :contentReference[oaicite:13]{index=13}.
• Rare neurologic signs (seizures) suggest caution in seizure-prone animals :contentReference[oaicite:14]{index=14}.

🚫 5. Contraindications & Precautions

• Avoid if history of dry eye, seizure disorders, or allergy.
• Use cautiously in pregnant, lactating, hepatic/renal impaired pets (lack safety data) :contentReference[oaicite:15]{index=15}.
• No major drug interactions reported—still disclose all meds and supplements :contentReference[oaicite:16]{index=16}.

🩺 6. Monitoring & Follow‑Up

• For coccidiosis: recheck fecal floats 3–5 days post-treatment; consider repeat course if oocyst load remains :contentReference[oaicite:17]{index=17}.
• For systemic infections: monitor neurologic signs, appetite, hydration; full bloodwork as needed.
• Track signs of ocular dryness, GI distress, lethargy, or new neurologic events.

📝 7. Client Education & Home Care

• Explain off-label use and importance of dosing accuracy.
• Demonstrate paste administration or syringe use for suspension.
• Emphasize monitoring for GI upset, eye changes, or seizures.
• Advise owners not to double dose if missed.
• Recommend using Ask A Vet app for dosing reminders, symptom logs, and vet access 😊.

📌 8. 2025 Vet Takeaways

• Ponazuril is a versatile extra-label antiprotozoal useful in coccidiosis and systemic protozoal diseases in dogs and cats.
• Dose for coccidia at 20–50 mg/kg daily for 2–5 days; for systemic disease, 7.5–15 mg/kg for weeks to months.
• GI upset and dry eye are common; rare seizures or skin reactions warrant discontinuation.
• Follow-up fecals or clinical monitoring needed; adjust treatment as required.
• Educate owners thoroughly and offer digital support tools like Ask A Vet to boost compliance and outcomes 😊.

At Ask A Vet, we provide dosing calculators, treatment reminders, symptom trackers, and 24/7 vet messaging to support safe and effective ponazuril therapy. Encourage owners to download our app for confident protozoal infection management ❤️