Omeprazole for cats: Dosage and safety

In this article:

• What is omeprazole used for in cats?
• Is omeprazole safe for cats?
• Omeprazole dosage for cats
• Omeprazole alternatives for cats
• Summary

In this article

• What is omeprazole used for in cats?
• Is omeprazole safe for cats?
• Omeprazole dosage for cats
• Omeprazole alternatives for cats
• Summary

Omeprazole is a stomach acid reducer. Most people are familiar with it as the brand name heartburn drug Prilosec OTC. It works by blocking the stomach’s acid production, reducing irritation and erosion of the stomach lining. Veterinarians use it off-label in cats to treat ulcers or acid irritation and erosion of the esophagus (esophagitis). Veterinarians rarely encounter stomach ulcers in cats, but esophagitis is a more common problem usually caused by acid reflux. Omeprazole’s side effects are minimal. However, studies in mice have shown some concern for long-term use, so veterinarians try to limit its use to no longer than four weeks.

RELATED: Save up to 80% on omeprazole

What is omeprazole used for in cats?

Omeprazole is commonly prescribed to treat or prevent ulcers or esophagitis in cats. It works by reducing gastric acid secretion. It belongs to a class of drugs called proton pump inhibitors, or PPIs. These drugs block the proton pump in the cells lining the stomach, which releases hydrogen protons into the stomach to create an acid environment. By reducing acid content, omeprazole gives the stomach or esophageal lining time to heal. 

Unlike an antacid, omeprazole reduces gastric acid after a meal and continues to work between meals. It works for a long time—usually two or three days—because it collects around the cells in the stomach. 

Omeprazole for ulcers

Unlike people and dogs, ulcers are uncommon in cats. When cats have gastrointestinal ulcers, the most likely cause is cancer, infection, parasites, poisoning, ulcer-causing drugs like nonsteroidal anti-inflammatory drugs (NSAIDs), or a foreign object in the stomach. 

While keeping in mind that stomach ulcers in cats are usually part of a larger and sometimes very serious medical condition, the most common symptoms cats with ulcers have are:

• Vomiting
• Blood in the vomit
• Black and tarry stools
• Appetite loss
• Weight loss
• Anemia
• Gas
• Diarrhea

Veterinarians can only definitively diagnose stomach or duodenal ulcers from an endoscopic examination. Once an ulcer has been diagnosed, veterinarians will try to find and treat the underlying cause. Omeprazole is a drug of choice for reducing stomach acid to help the ulcer heal. 

Omeprazole for esophagitis

Unlike ulcers, esophagitis (irritation and swelling of the esophageal lining) is common in cats. It is usually caused by acid reflux disease, a condition in which stomach contents, including acid, back up into the esophagus. Other causes include caustic chemicals, foreign objects, and anesthesia.

Like most cat diseases, esophagitis is difficult for owners to spot. The most typical symptoms are behavior changes that signal the cat is not feeling well. More specific symptoms of feline esophagitis include: 

• Regurgitation
• Swallowing problems
• Excessive swallowing
• Painful swallowing
• Excessive salivation

As with stomach ulcers, veterinarians can only definitively diagnose esophagitis from an endoscopic examination. Treatments include a soft food diet, drugs to reduce reflux, and a stomach acid reducer. Omeprazole is usually the first choice as an acid suppressant, but histamine blockers also work well and have fewer adverse effects. Other drugs, such as an antibiotic or stomach protectant, may also be added.

Is omeprazole safe for cats?

Omeprazole is safe to use in cats for a limited time—four weeks or less. It isn’t safe for all cats. Any cat that has had an allergic reaction to omeprazole shouldn’t take the drug. Because omeprazole is eliminated by the liver and kidneys, veterinarians will sometimes reduce the dose in cats with liver problems or kidney disease. 

Side effects of omeprazole in cats

The most common side effects of omeprazole in cats are generally mild and include:

• Decreased appetite
• Colic
• Nausea
• Vomiting
• Gas
• Diarrhea

Omeprazole also increases liver enzymes in the blood. Veterinary professionals do not consider this a threat, but you should inform any veterinarian treating the cat about omeprazole treatment before any blood tests are given.

More serious side effects are rare but could include:

• Blood disorders
• Neurologic changes
• Protein in the urine

Interactions of omeprazole with other pet meds

Omeprazole has so many drug interactions that it’s very important that pet parents inform the veterinarian about everything the cat takes. This includes prescription drugs, over-the-counter medications, dietary supplements, and herbal remedies. 

Omeprazole drug interactions fall into two categories: drugs that don’t work well when taken with omeprazole and drugs that are more likely to cause side effects when combined with omeprazole.

Omeprazole slows the breakdown of many other drugs, making them more likely to cause side effects. The dosages of these other drugs may need to be adjusted. These include: 

• Benzodiazepines such as diazepam
• Antiseizure drugs
• The antibiotic clarithromycin
• The immune-suppressing drug cyclosporine
• The blood thinner warfarin
• The heart failure drug digoxin.

Because omeprazole reduces stomach acid, some drugs don’t get adequately digested in the stomach. As a result, the animal gets less of the drug into their system. These drugs include:

• The antibiotic ampicillin
• The antifungal drug ketoconazole
• Iron supplements
• Vitamin B12

Omeprazole dosage for cats

The standard omeprazole dosage for cats is 0.5–1 mg/kg, administered once daily. This is the recommended dosage for gastric ulcers and esophagitis. Some recommendations call for slightly higher doses or for two doses per day, so dosages may vary by veterinarian. 

Human versions of omeprazole come as tablets, capsules, or oral suspensions. These human versions are the same ones that your vet may prescribe for your cat. There’s also an omeprazole oral paste sold under the brand names UlcerGard and GastroGard. Both are formulated in doses appropriate for horses, so they aren’t used in cats. 

Can cats overdose on omeprazole?

Do not give a cat too much omeprazole. It’s unlikely to cause serious problems unless the overdose is massive. However, you should still call a veterinarian or pet poison helpline if you think the cat has been given too much omeprazole. 

Can I give my cat omeprazole every day?

Cats should be given daily doses of omeprazole, but only for a few weeks. Do not miss doses. Veterinarians are advised that cats should not take omeprazole for longer than four weeks. Some veterinarians may extend treatment longer than that but are unlikely to go beyond eight weeks, the maximum treatment length for dogs.

How to give your cat omeprazole

Dosing a cat with omeprazole is straightforward:

• Follow all the veterinarian’s instructions.
• Give the cat every dose for the full length of time prescribed.
• Administer the dose every day in the morning before the cat’s morning meal.
• Give the dose before the cat has eaten. If the cat throws up the dose, try giving it with food the next time.
• If you don’t know how to give a cat an omeprazole tablet or capsule, ask a veterinary technician at the vet’s office to demonstrate.
• If you are giving the cat omeprazole oral suspension, shake the bottle before measuring a dose. Always measure the dose with an oral syringe, which a veterinarian can provide for free.
• Do not miss a dose. If a dose of omeprazole is missed, give it when remembered. If it’s almost time for the next dose, skip the missed dose and give the next dose as scheduled. Never make up a missed dose by giving the cat two doses at once. 
• Store this medicine at room temperature in a light-resistant container.

Omeprazole alternatives for cats

Omeprazole is a preferred treatment for cats with ulcers. If omeprazole is not an option, veterinarians can use other acid suppressants, including:

• Other proton pump inhibitors: The American College of Veterinary Internal Medicine (ACVIM) considers proton pump inhibitors like omeprazole to be the best option for treating dogs and cats with ulcers or esophagitis. In addition to omeprazole, veterinarians can use pantoprazole, lansoprazole, or esomeprazole in cats. Some of these are not as effective as omeprazole in cats.
• Histamine 2 receptor antagonists (H2 blockers): H2 blockers also block stomach acid production. Veterinarians are most likely to prescribe famotidine, which is sold over the counter as a generic or brand-name Pepcid or Zantac. 
• Antacids: Cats can take most antacids, but they are not considered effective as a treatment for ulcers and esophagitis in cats. Given with a meal, they neutralize stomach acid. They can also be used with omeprazole, provided they are given two hours before or two hours after the omeprazole dose.
• Sucralfate: The veterinarian could also use sucralfate to prevent or treat ulcers in cats. This drug works by reacting with the acid in the stomach and forming a protective barrier over the stomach lining.

Summary

Cats can safely be given omeprazole for a few weeks for ulcers or esophagitis. The treatment requires daily doses given once or twice a day. Give the cat each day’s dose at least 30 minutes before eating. If doses are given once per day, give the dose before the cat eats in the morning.