Medication Guide • Reviewed by Dr. Tiffany Delacruz, DVM
Omeprazole (Prilosec) for Dogs
Omeprazole is a strong acid reducer used in dogs for ulcers, severe acid reflux, and protection of the stomach in dogs taking NSAIDs or steroids long-term.
What Omeprazole (Prilosec) is used for in dogs
- Stomach ulcers
- Severe acid reflux
- Erosive esophagitis
- NSAID-associated GI protection
How it works
Omeprazole blocks the proton pump in stomach cells, dramatically reducing acid production (90%+).
Available formulations
10 mg tablet (OTC)
20 mg capsule
Compounded liquid
Side effects to know
Common side effects
- • Mild GI upset
- • Decreased appetite
- • Diarrhea
These usually resolve on their own. If they persist past the first few doses, ask your vet.
Call your vet immediately if you see
- ⚠ Long-term overuse may affect bone density or B12 absorption (rare in dogs)
Drug interactions
- • Reduces absorption of some drugs (e.g. ketoconazole)
- • Increases plasma levels of others
When not to use
- • Severe liver disease
- • Documented hypersensitivity
Monitoring during treatment
Long-term use should be supervised — taper rather than stop abruptly when discontinuing.
Talk to a vet about Omeprazole (Prilosec)
RexVet is the first 501(c)(3) non-profit online vet service in the U.S. Talk to a licensed veterinarian by video for $64.99 per visit.
Book a vet visit — $64.99Omeprazole (Prilosec) for Dogs
Frequently asked questions
Can I give my dog Prilosec?
Yes — at vet-determined doses. The 10 mg OTC tablet is often used in medium-sized dogs.
How long does omeprazole take to work?
Effect builds over 3-5 days. Some dogs feel relief within hours, but full acid suppression takes a few days.
Should I give omeprazole with food?
Best given 30-60 minutes before food on an empty stomach for maximum effect.
Can RexVet prescribe omeprazole?
Not after a video visit alone. Omeprazole is a human-labeled drug, so a veterinarian needs to examine your pet in person before prescribing it.
Can I give omeprazole long-term?
For most dogs yes — but always under vet supervision. Long-term use can affect mineral absorption; periodic bloodwork is a good idea.
Medical review by Dr. Tiffany Delacruz, DVM
Chief Executive Officer & Lead Veterinarian, RexVet. Licensed in Florida, New York, and Virginia.
Last fact-checked: 2026-05-19
Sources
This page is an educational reference and does not replace veterinary advice. Always consult a licensed veterinarian before starting, changing, or stopping medication for your pet.