Omeprazole for Pets

Omeprazole is a stomach-acid reducing medication that veterinarians may prescribe for dogs and cats with ulcers, stomach irritation, or other acid-related digestive problems. It is commonly used in small animal practice as an extra-label medication under veterinary supervision.

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Quick Facts

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Drug class

Proton pump inhibitor (PPI); an acid reducer that lowers stomach acid production.

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Common brand names

Prilosec®, Losec®, and Gastrogard® [equine brand]. Human formulations are commonly used in dogs and cats.

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Common forms

Most often given by mouth as tablets or capsules. It may also be compounded into other oral forms when needed.

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Species used in

Dogs and cats. In small animals, use is generally extra-label and should follow a veterinarian’s instructions.

What Omeprazole Is Used For

Omeprazole is used to reduce stomach acid in pets with acid-related digestive conditions. Veterinarians commonly prescribe it for stomach or upper small intestinal ulcers, gastritis, and to help prevent or treat gastric erosions linked to medications such as NSAIDs. It may also be part of treatment plans for some pets with reflux or other conditions where reducing acid helps protect the stomach lining. Omeprazole works by blocking the proton pumps in the stomach’s acid-producing cells, which decreases acid production. In veterinary medicine, proton pump inhibitors are generally considered more effective than H2 blockers for treating gastrointestinal ulcer disease. Long-term use should only be continued if your veterinarian specifically recommends it, because prolonged acid suppression may not be appropriate for every pet.

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Side Effects to Watch For

Common side effects can include vomiting, decreased appetite, gas, and diarrhea.
Some pets may develop digestive upset if the medication does not agree with them.
Allergic reactions are uncommon but can happen; signs may include facial swelling, hives, trouble breathing, or sudden collapse.
Overdose or severe reactions may cause marked vomiting, severe lethargy, weakness, or other unusual signs that need urgent veterinary attention.
Use extra caution in pets with liver disease, kidney disease, or in pets that are pregnant or nursing unless your veterinarian has advised its use.
Drug interactions are possible, so your vet should know about all medications, supplements, and herbal products your pet receives.

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Dosing & Administration

Always follow your vet’s instructions exactly. Do not guess the dose, frequency, or treatment length. Omeprazole is usually given by mouth, and many veterinarians recommend giving it on an empty stomach before the first meal of the day. If your pet vomits when it is given on an empty stomach, your veterinarian may advise giving future doses with food. Do not crush or allow your pet to chew delayed-release tablets or capsules unless your veterinarian or pharmacist specifically tells you the product can be handled that way. If you miss a dose, skip the missed dose and give the next dose at the regular time unless your veterinarian tells you otherwise. Do not give two doses at once. Do not stop the medication early or continue it longer than prescribed without checking with your vet.

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When to Call a Vet

Emergency

Go to the ER now

● Trouble breathing, facial swelling, hives, collapse, or other signs of an allergic reaction
● Suspected overdose or your pet got into the bottle
● Repeated vomiting, profound weakness, collapse, or severe lethargy after taking the medication
● Black, tarry stool, vomiting blood, or signs of severe stomach bleeding

Urgent

See a vet within 24 hours

● Vomiting, diarrhea, poor appetite, or gas that is persistent, worsening, or severe
● Your pet seems painful, refuses food, or is not improving on treatment
● You accidentally gave the wrong amount or gave doses too close together
● Your pet has liver disease, kidney disease, is pregnant, or is nursing and is having any new symptoms

Monitor

Watch at home, call if it worsens

● Mild stomach upset that is brief and your pet otherwise seems normal
● Questions about giving the medication with or without food
● A missed dose when your pet is otherwise acting normally
● Needing help giving tablets or capsules safely

Common Questions About Omeprazole

Can I give my dog human omeprazole?

Only if your veterinarian tells you to. Veterinarians sometimes use human omeprazole products for dogs, but the correct product, schedule, and duration depend on your dog’s condition and any other medications they take. Some formulations are not ideal for every pet, so call your vet before using anything from your medicine cabinet.

What happens if I miss a dose?

In many cases, you should skip the missed dose and resume the regular schedule at the next dosing time. Do not give two doses at once unless your veterinarian specifically instructs you to do so. If you miss doses often, contact your vet for advice.

Can my cat take omeprazole?

Yes, veterinarians may prescribe omeprazole for cats when it is appropriate. In cats, as in dogs, it is generally used extra-label and should only be given under veterinary guidance.

How long does omeprazole take to work?

It may begin working within one to two days, although the time to visible improvement depends on why it was prescribed. If your pet is not improving, or is getting worse, contact your veterinarian.

Should omeprazole be used long term?

Not unless your veterinarian specifically recommends it. Veterinary references note that prolonged acid suppression may not be appropriate for every patient, and pets on longer courses may need reassessment or a taper plan rather than abrupt discontinuation.

Sources

Disclaimer: The information provided in this article is for educational purposes only and does not constitute veterinary medical advice. Reading this content does not establish a veterinarian-client-patient relationship. Every pet is different — always consult a licensed veterinarian before making decisions about your pet's health, diet, or care. If you'd like personalized guidance, you can talk to one of our vets. If your pet is experiencing a medical emergency, contact your local emergency animal hospital immediately.

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