VETINUITY
Why twice a day instead of once?
Intragastric pH work in dogs and cats shows that 1 mg/kg every 12 hours keeps pH above the target for more of the day than the same total dose given once.
● ANSWER
Sourced & dated
What is the omeprazole dose for dogs and cats?
Omeprazole is dosed at 1 mg/kg by mouth every 12 hours in dogs and cats, given 30-60 minutes before a meal, and tapered rather than stopped after courses longer than 3-4 weeks.
● VETINUITY OMEPRAZOLE DOSE CALCULATOR
Vetinuity omeprazole dose calculator
Round to the nearest available capsule or a compounded strength; do not split enteric-coated pellets into a powder.
● WHAT'S DOCUMENTED
Omeprazole for dogs and cats is 1 mg/kg by mouth every 12 hours, half an hour to an hour before food, per Vetinuity’s omeprazole dose table and calculator above. It is the oral proton pump inhibitor the 2018 ACVIM consensus treats as the reference drug for acid suppression in small animals, ahead of famotidine.
Omeprazole doses by indication
| Indication | Dog | Cat | Route and frequency |
|---|---|---|---|
| Gastroduodenal ulceration or erosion | 1 mg/kg | 1 mg/kg | PO q12h, 4-8 weeks |
| Reflux esophagitis | 1 mg/kg | 1 mg/kg | PO q12h, with a prokinetic as indicated |
| Discharge after IV pantoprazole | 1 mg/kg | 1 mg/kg | PO q12h, reassess at recheck |
Formulations and how to give them
Human capsules (10, 20, 40 mg) contain enteric-coated pellets; opening the capsule and dosing a fraction of the pellets works, but crushing them exposes the drug to acid and destroys it. Over-the-counter 20 mg delayed-release tablets are an alternative for larger dogs. In cats, a crossover study of oral acid suppressants found the proton pump inhibitors, omeprazole among them, raised intragastric pH more than famotidine. Give it before a meal because the drug only blocks pumps that food has switched on.
When not to use it
The consensus does not support acid suppression for every vomiting dog. Pancreatitis without ulceration, chronic kidney disease without evidence of GI bleeding, and hepatic disease alone are not indications. Steroids alone are not either; the combination of a corticosteroid with an NSAID, or an NSAID overdose, is. Long courses alter gut flora and may lower calcium, B12 and iron absorption.
Interactions and tapering
In people omeprazole inhibits the liver enzyme that activates clopidogrel and blunts its antiplatelet effect; the size of that effect in dogs and cats is uncertain, so monitor patients on both. Taper over 1 to 2 weeks after more than 3 to 4 weeks of therapy. The table is published by Vetinuity, the clinical assistant created by emergency veterinarian Brian Toncray, DVM.
Related: pantoprazole, famotidine, sucralfate, NSAID overdose and meloxicam.
● SOURCES
- 1. Marks SL, Kook PH, Papich MG, et al. ACVIM consensus statement: Support for rational administration of gastrointestinal protectants to dogs and cats. J Vet Intern Med. 2018;32(6):1823-1840. PMID 30378711. Proton pump inhibitors: dosing, duration and discontinuation. Checked 2026-10-26.
- 2. Parkinson S, Tolbert K, Messenger K, et al. Evaluation of the effect of orally administered acid suppressants on intragastric pH in cats. J Vet Intern Med. 2015;29(1):104-112. PMID 25537303. Results: omeprazole formulations. Checked 2026-10-26.
- 3. Tolbert K, Stubbs E. Rational use of gastroprotectants in cats: An evidence-based approach. J Feline Med Surg. 2024;26. PMID 39105658. Proton pump inhibitors in cats. Checked 2026-10-26.
● RELATED ANSWERS
- Pantoprazole (Protonix) IV Dose for Dogs and Cats
Pantoprazole is given at 1 mg/kg IV over 15 minutes every 12 hours in dogs and 1 mg/kg IV every 12-24 hours in cats, switching to an oral PPI once the patient eats.
- Famotidine (Pepcid) Dose for Dogs and Cats
Famotidine is dosed at 0.5-1 mg/kg PO or slow IV every 12 hours in dogs and cats; twice-daily dosing matters because once-daily famotidine barely moves gastric pH.
- Sucralfate (Carafate) Dose for Dogs and Cats
Sucralfate is a fixed dose, not a per-kilogram one: 0.5-1 g per dog by mouth every 8-12 hours and 0.25 g per cat every 8-12 hours, given 2 hours apart from other oral drugs.
- Ibuprofen and NSAID Overdose in Dogs: Toxic Doses
Ibuprofen causes GI signs in dogs from 100-125 mg/kg, renal failure from 175-300 mg/kg, CNS signs above 400 mg/kg and can be lethal above 600 mg/kg; naproxen is toxic at far lower doses.
- Meloxicam Dose for Dogs and Cats (Metacam)
Meloxicam is dosed at 0.2 mg/kg once, then 0.1 mg/kg once daily in dogs; in US cats the label allows a single 0.3 mg/kg SC injection only, while some other countries label 0.05 mg/kg PO daily long term.
● FAQ
Can a dog stop omeprazole suddenly?
After more than 3 to 4 weeks, taper the dose over a week or two; abrupt withdrawal can cause rebound acid hypersecretion.
● OPEN APP
SEE HOW VETINUITY HANDLES THIS.
Vetinuity explains clinical options with journal citations.
The veterinarian diagnoses and prescribes.