Omeprazole (Prilosec, GastroGard) for Pets in 2025 🐶🐱

Omeprazole is one of the most powerful veterinary antacids available, often prescribed for pets with ulcers, reflux, or chronic stomach irritation. I’m Dr Duncan Houston BVSc, and in this 2025 guide, I’ll explain how to use Omeprazole safely in dogs and cats, its best applications, and when to proceed with caution 💊

🧪 What Is Omeprazole?

Omeprazole is a proton pump inhibitor (PPI), meaning it shuts down acid production at its source—within the stomach’s parietal cells. Unlike antacids that neutralize existing acid, Omeprazole prevents the production of new acid.

It’s available under brands like:

• Prilosec® (human version)
• GastroGard® and Ulcergard® (equine/feline formulations)
• Zegerid® (buffered powder form)

📋 When Omeprazole Is Used

• 🩸 Stomach ulcers in dogs, cats, and horses
• 🌡️ Gastritis (inflammation of the stomach lining)
• 🦠 Treatment of Helicobacter as part of “triple therapy”
• 🚫 Reflux esophagitis
• 🧪 Reduction of cerebrospinal fluid pressure (specialist use)

🕒 Dosing and Administration

• 📆 Typically given twice daily for ulcer treatment
• ⏳ Takes 3–5 days to reach full effect
• 🍽️ Best given on an empty stomach before the first meal
• 🧃 May be given with fruit juice, but do not crush tablets or pellets

If You Miss a Dose:

• Give when remembered, then resume normal schedule
• 🚫 Do not double the next dose

⚠️ Side Effects

Omeprazole is usually well-tolerated, but potential side effects include:

• 🐾 Appetite loss
• 💨 Gas and bloating
• 💩 Diarrhea
• 📈 Mild increase in liver enzymes (non-harmful but noteworthy on blood tests)

Rarely, it can reduce cerebrospinal fluid production, which may be helpful in pets with hydrocephalus or syringomyelia.

🔄 Drug Interactions

Omeprazole interacts with many medications through the cytochrome P450 system and by altering stomach pH:

• ⬆️ Increases levels: diazepam, alprazolam, phenytoin, warfarin
• ⬇️ Reduces absorption: ketoconazole, ampicillin
• ⬆️ Cyclosporine levels may increase
• 🚫 May interfere with clopidogrel activation (blood thinner)

🚫 When to Use Caution

• 🐶🐱 Not recommended for more than 4 consecutive weeks in most cases
• 🚫 Avoid in pets with liver or kidney disease unless dosage is adjusted
• 🚫 Safety not established in pregnant or lactating animals
• 🚫 Do not use if tablets need to be crushed—ask your vet for a liquid or alternate form

🧪 Monitoring and Safety

• 🩺 If used long-term, monitor liver enzymes and electrolytes
• 📊 Watch for signs of rebound hyperacidity when stopping after prolonged use
• 🧬 Avoid long-term use in pets prone to infections or nutrient malabsorption

📲 Ask a Vet for Help

Not sure if your pet's GI symptoms need omeprazole? Use the Ask A Vet app for immediate answers from licensed veterinarians about ulcers, acid suppression, or safe alternatives 🐾💬

✅ Summary

• ✔️ Potent acid suppressant for dogs and cats
• ✔️ Used to treat ulcers, reflux, and Helicobacter infections
• ✔️ Best used for short-term (4-week) treatment
• ⚠️ Monitor for drug interactions and avoid in long-term unmonitored use

Need help managing your pet’s GI condition? Reach out anytime with the Ask A Vet app to speak directly to expert veterinarians 🩺🐶🐱

— Dr Duncan Houston BVSc