Omeprazole for Dogs & Cats: Acid Reflux & Ulcer Treatment

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Omeprazole is a proton pump inhibitor (PPI). It lowers the amount of acid the stomach makes by blocking the acid pump in stomach cells. In dogs and cats, your vet may prescribe it when excess stomach acid is contributing to irritation, reflux, or ulcer formation.

In veterinary medicine, omeprazole is commonly used extra-label, which means vets use a human medication in a medically accepted way for pets. That is common in small animal practice. Human tablets and capsules are often used, and some pets need a compounded form if standard products are hard to give.

This medication is not a cure-all for vomiting. It helps in situations where acid reduction is likely to matter, such as stomach or upper intestinal ulcers, esophagitis from reflux, or gastritis in selected cases. Your vet may also pair it with other treatments, like diet changes, anti-nausea medication, or a stomach protectant, depending on the cause.

Your vet may use omeprazole for gastric or duodenal ulcers, acid reflux, esophagitis, and some cases of gastritis. It is also used to help prevent or treat stomach irritation linked to certain medications, especially NSAIDs in pets that are at risk for erosions or ulcers.

In dogs, omeprazole may also be part of a treatment plan for Helicobacter-associated stomach disease or severe upper GI irritation. In both dogs and cats, it is often chosen when stronger acid suppression is needed than an H2 blocker like famotidine can provide.

That said, not every vomiting pet needs an acid reducer. Vomiting can come from diet changes, pancreatitis, intestinal disease, kidney disease, toxin exposure, or many other problems. Omeprazole works best when your vet believes stomach acid is part of the picture, not as a one-size-fits-all answer.

Omeprazole dosing varies by species, body weight, formulation, and the reason your pet is taking it. Published veterinary references list 0.5-1 mg/kg by mouth every 12-24 hours in dogs and cats, but your vet may adjust that based on the condition being treated and how your pet responds. Never change the dose on your own.

It is usually given by mouth on an empty stomach, before the first meal of the day. If your pet vomits when it is given on an empty stomach, ask your vet whether giving it with a small amount of food makes more sense. Tablets and capsules generally should not be crushed or chewed, because that can affect how the medication works.

Omeprazole does not always help right away. Acid suppression improves over one to two days, and visible symptom improvement may take longer. If your pet has been on omeprazole for more than 3-4 weeks, your vet may recommend a taper instead of stopping abruptly, because rebound acid production can happen after prolonged use.

Many pets tolerate omeprazole well, but side effects can happen. The most commonly reported ones are vomiting, decreased appetite, gas, and diarrhea. Mild stomach upset may improve if the dosing plan is adjusted, but any ongoing problem should be reported to your vet.

Call your vet promptly if your pet seems weaker than usual, refuses food, vomits repeatedly, develops black or bloody stool, or acts painful. Those signs may point to the underlying GI problem getting worse rather than a medication side effect.

Pets with liver disease, kidney disease, pregnancy, or nursing status may need extra caution. Long-term acid suppression is also not ideal for every patient. In veterinary references, prolonged PPI use is approached carefully because of concerns about rebound acid secretion after stopping and possible effects on the GI environment over time.

Omeprazole can interact with other medications, so your vet should review every prescription, supplement, probiotic, and herbal product your pet takes. Veterinary references specifically advise caution with benzodiazepines, certain antibiotics, clopidogrel, cyclosporine, diuretics, levothyroxine, and phenobarbital.

There are two main reasons interactions matter. First, omeprazole changes stomach acidity, which can affect how some oral drugs are absorbed. Second, it can affect liver enzyme activity, which may change how some medications are processed in the body.

Timing also matters with stomach protectants. If your pet is taking sucralfate, your vet may want the medications separated because sucralfate can reduce absorption of some oral drugs. Do not add over-the-counter acid reducers or antacids unless your vet says they fit safely into the plan.