Omeprazole (Prilosec) for Dogs: A Medication for Acid Reflux and Stomach Ulcers

If your dog was diagnosed with acid reflux or stomach ulcers, then a veterinarian may prescribe omeprazole (Prilosec). Omeprazole is a medication that can reduce stomach acid. It’s usually well tolerated by dogs, and it doesn’t cause many side effects.

Below, learn what omeprazole is, how it works, and everything else you need to know.

Omeprazole for dogs at a glance

What is omeprazole for dogs, and what is it used for?

Omeprazole is a medication used in dogs to treat ulcers in the stomach and upper intestines. It does so by reducing stomach acid, which irritates stomach ulcers. The brand name of omeprazole is Prilosec, which you might recognize as a human-brand medicine.

Omeprazole is considered a “gastric protectant,” meaning it can be used to protect the stomach in dogs with conditions such as:

• Acid reflux

• Acute stomach inflammation

• Bilious vomiting syndrome

• Gastritis associated with liver or kidney disease

• Toxic substance ingestion

• Esophagus inflammation

• Exocrine pancreatic insufficiency

• Regurgitation resulting from several causes, including megaesophagus

• Stomach issues caused by nonsteroidal antiinflammatory drugs (NSAIDs)

• Gastrointestinal infections with Helicobacter bacteria

Omeprazole is part of a class of medications called proton-pump inhibitors. Proton-pump inhibitors block a type of enzyme that produces stomach acid. Omeprazole doesn’t block all stomach acid; dogs still have enough stomach acid to digest food.

Most often, omeprazole is prescribed for shorter-term use in dogs. Evidence suggests it’s best for dogs to take the medicine for 8 weeks or less. This helps protect your pup from more serious risks from taking the medication regularly for a long time.

Omeprazole is available for dogs over the counter and by prescription. It’s not FDA approved for dogs, so veterinarians prescribe omeprazole off-label. This is common in veterinary medicine.

What is the dosage of omeprazole for dogs, and how is it given?

Omeprazole is most often given to dogs once a day, but it may be given twice a day. The standard dosage is either 20 mg once daily or 0.5 mg to 1.5 mg per kilogram of body weight once daily. A veterinarian will give you the correct dosage for your dog.

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Omeprazole is available in several forms, including:

• Tablets 

• Capsules

• Oral liquid 

• Paste

Omeprazole can be compounded into a flavored form to make it easier to give to dogs. 

The medication generally takes 3 to 5 days to take full effect and improve symptoms. 

If your dog has been taking omeprazole for more than 3 weeks, do not suddenly stop giving the medication. Gradually reduce your dog’s dosage. A veterinarian can give you instructions on how to do this safely. Do not suddenly stop giving your dog the medication, since this can cause serious side effects.

How to give omeprazole to dogs

Do not crush omeprazole tablets or capsules, and do not let your pet chew the medication. Omeprazole tablets have a coating to protect the medication from stomach acid. Crushing the medication will likely reduce how well it works.

Omeprazole should be given to dogs on an empty stomach first thing in the morning before breakfast. If your dog vomits or loses their appetite after you give them omeprazole, it can be given with food.

What should you do if your dog misses a dose of omeprazole? 

If you miss giving your dog a dose of omeprazole, give it as soon as you remember. Then continue their regular dosing schedule the next day. Never give an extra dose to catch up.

What are the common side effects of omeprazole in dogs?

The most common side effects of omeprazole in dogs are usually mild and can include: 

• Diarrhea

• Reduced appetite

• Passing more gas

• Vomiting

If you notice any side effects in your pet, call a veterinarian. They can give you guidance on ways to reduce side effects or suggest a different medication. Negative side effects should improve within 24 hours, but they may take longer in dogs with liver or kidney disease.

What are the most serious risks of omeprazole for dogs?

Omeprazole can cause serious risks in dogs, usually if your dog takes the medication for longer than 8 weeks. Some evidence suggests that omeprazole can change the balance of your dog’s gut or stomach lining. Because of these risks, a veterinarian will likely limit how long your dog takes omeprazole.

If your dog has taken the medication for longer than 3 weeks, it shouldn’t be stopped abruptly. This can lead to a sudden increase in stomach acid that you want to avoid. Work with your veterinarian to find the safest plan for your pup.

Does omeprazole interact with other dog medications?

Omeprazole can interact with several other medications and supplements dogs may take, including:

• Benzodiazepines, such as alprazolam

• Cyclosporine

• Digoxin

• Diuretics, such as furosemide

• Warfarin

• Phenobarbital

• Levothyroxine

• Clopidogrel

• Some antibiotics

• Vitamin B

• Antihistamines

• Phenytoin 

Omeprazole also should not be given at the same time as medication that depends on stomach acid to be absorbed in your dog’s body. These medications include azole antifungal medications (ketoconazole, itraconazole) and iron supplements. 

Tell a veterinarian about medications or supplements that your dog takes before they are prescribed omeprazole. This will help the vet reduce the risk of interactions.

Why trust our experts?

Written by:

Sarah J. Wooten, DVM, CVJ

Dr. Sarah Wooten, DVM, CVJ, is a well-known international influencer in the veterinary and animal healthcare spaces. She has 16 years of experience in private practice and more than 15 years experience in veterinary media work.

Edited by:

Renée Fabian, MA

Renée Fabian is the senior pet health editor at GoodRx. She’s worked for nearly 10 years as a journalist and editor across a wide range of health and well-being topics.

Reviewed by:

Ghanasyam Bey, DVM

Ghanasyam Bey, DVM, is from Cleveland, Ohio, and attended Princeton University for undergraduate studies. After a year of biology research at Duke University, he attended Ohio State College of Veterinary Medicine.

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