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Omeprazole

Prescription
Proton pump inhibitor (PPI)
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
4 available
Interactions
2 documented
Formulations
4

Mechanism of action

Irreversibly inhibits the H+/K+ ATPase (proton pump) in gastric parietal cells, reducing gastric acid secretion

At a glance

Class
Proton pump inhibitor (PPI)
Schedule
Prescription
Storage
Store below 25°C, protect from light and moisture. Do not crush enteric-coated tablets.

Dosing

🐕

Dog

Gastric/duodenal ulcers, NSAID gastroprotection
Dose
0.5–2 mg/kg
Route
PO
Frequency
SID-BID
Max dose
40 mg/dose; 80 mg/day
Duration: 2-8 weeks
Gastroesophageal reflux
Dose
1–2 mg/kg
Route
PO
Frequency
SID-BID
Max dose
40 mg/dose; 80 mg/day
Duration: 4-8 weeks
🐈

Cat

Gastric ulcers, acid reflux
Dose
0.5–1.5 mg/kg
Route
PO
Frequency
SID-BID
Max dose
10 mg/dose; 20 mg/day
Duration: 2-4 weeks

Formulations

💊

Capsule — 1

Strength
20mg
Available in India
💊

Tablet (enteric coated) — 1

Strength
20mg
Available in India
💉

Injectable — 1

Strength
40mg vial
Available in India
🧴

Oral suspension — 1

Strength
2mg/mL
Available in India

Storage

Store below 25°C, protect from light and moisture. Do not crush enteric-coated tablets.

Safety

Absolute contraindications — do not use

  • Known hypersensitivity to PPIs
    Cross-reactivity with other PPIs possible

Use with caution

  • Concurrent drugs requiring acidic pH for absorption
    Reduced absorption of acid-dependent drugs
  • Long-term use
    Chronic acid suppression may affect calcium/magnesium absorption and alter GI microbiome

Adverse effects

Common
Diarrhoea
Nausea
Flatulence
Serious
Rebound acid hypersecretion on discontinuation
Vitamin B12 deficiency (chronic use)

Monitoring parameters

Clinical responseGI signsConsider gradual taper for courses >4 weeks

Interactions

Moderate — 2

Sucralfate
moderate
Sucralfate requires acidic environment for activation; omeprazole raises gastric pH, reducing sucralfate efficacy
Management: Administer sucralfate 30-60 minutes before omeprazole if both required.
Clopidogrel
moderate
Omeprazole inhibits CYP2C19, reducing conversion of clopidogrel prodrug to its active metabolite, potentially decreasing antiplatelet efficacy.
Management: Use pantoprazole or famotidine instead of omeprazole when patient requires both gastroprotection and clopidogrel antiplatelet therapy.

Brands

International

GastroGard
Boehringer Ingelheim
Prilosec
AstraZeneca

India

Omez
Dr. Reddy's
Pan
Alkem

FAQs

Frequently asked questions

›What is Omeprazole?
Omeprazole is a proton pump inhibitor (ppi) used in pets. Irreversibly inhibits the H+/K+ ATPase (proton pump) in gastric parietal cells, reducing gastric acid secretion
›What is Omeprazole used for in pets?
Omeprazole is used in veterinary medicine for: Gastric/duodenal ulcers, NSAID gastroprotection; Gastroesophageal reflux; Gastric ulcers, acid reflux.
›What is the Omeprazole dose for dogs?
For dogs, Omeprazole is typically dosed as follows — Gastric/duodenal ulcers, NSAID gastroprotection: 0.5–2 mg/kg PO SID-BID; Gastroesophageal reflux: 1–2 mg/kg PO SID-BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Omeprazole dose for cats?
For cats, Omeprazole is typically dosed as follows — Gastric ulcers, acid reflux: 0.5–1.5 mg/kg PO SID-BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Omeprazole?
Common: Diarrhoea, Nausea, Flatulence. Serious (call your vet immediately): Rebound acid hypersecretion on discontinuation, Vitamin B12 deficiency (chronic use).
›Does Omeprazole need a prescription?
Yes. Omeprazole is a prescription medication and should only be administered under veterinary supervision.
›When should Omeprazole not be used?
Do not use Omeprazole if: Known hypersensitivity to PPIs.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Related medicines

Other medicines in the same class (Proton pump inhibitor).

Esomeprazole
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Irreversibly inhibits the H+/K+ ATPase proton pump in gastric parietal cells, profoundly suppressing gastric acid secretion
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Pantoprazole
Rx
Irreversibly inhibits H+/K+ ATPase in gastric parietal cells; preferred for IV administration due to better compatibility with IV fluids than omeprazole
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Rabeprazole
Rx
Irreversibly inhibits H+/K+-ATPase (proton pump) in gastric parietal cells, blocking the final step of gastric acid secretion. Effective regardless of stimulation pathway. More rapid onset than other PPIs.
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