Home/Medicines/Ampicillin
All medicines

Ampicillin

PrescriptionCDSCO approved
Aminopenicillin antibiotic
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Interactions
1 documented
Formulations
4

Mechanism of action

Inhibits bacterial cell wall synthesis by binding to PBPs; broader spectrum than penicillin G, including some gram-negative coverage

At a glance

Class
Aminopenicillin antibiotic
Schedule
Prescription
Storage
Store below 25°C; reconstituted injection use within 1 hour
CDSCO (India)
Vet-approved — 1975-01

Dosing

🐕

Dog

UTI / Respiratory / Soft tissue infections
Dose
10–40 mg/kg
Route
PO, IV, IM, SC
Frequency
TID to QID (q6–8h)
Max dose
1500 mg/dose; 6000 mg/day
Duration: 7–14 days
🐈

Cat

UTI / Respiratory / Soft tissue infections
Dose
10–40 mg/kg
Route
PO, IV, IM, SC
Frequency
TID to QID (q6–8h)
Max dose
500 mg/dose; 2000 mg/day
Duration: 7–14 days

Formulations

💊

Capsule — 2

Strength
250mg
Available in India
Strength
500mg
Available in India
💉

Injection (powder) — 2

Strength
500mg vial
Available in India
Strength
1g vial
Available in India

Storage

Store below 25°C; reconstituted injection use within 1 hour

Safety

Absolute contraindications — do not use

  • Known penicillin/ampicillin hypersensitivity

Use with caution

  • Concurrent bacteriostatic antibiotics
    May antagonize bactericidal activity

Adverse effects

Common
Diarrhoea
Nausea
Vomiting
Serious
Anaphylaxis
Superinfection
Bone marrow suppression (rare)

Monitoring parameters

Clinical responseCBC with prolonged useGI function

Interactions

Moderate — 1

Gentamicin
moderate
Synergistic antibacterial effect but additive nephrotoxicity risk
Management: Used intentionally for synergy against enterococci. Monitor renal function closely.

Brands

India

Ampilox
Zydus
Ampivet
Virbac India

International

Polycillin
Novartis

FAQs

Frequently asked questions

›What is Ampicillin?
Ampicillin is a aminopenicillin antibiotic used in pets. Inhibits bacterial cell wall synthesis by binding to PBPs; broader spectrum than penicillin G, including some gram-negative coverage
›What is Ampicillin used for in pets?
Ampicillin is used in veterinary medicine for: UTI / Respiratory / Soft tissue infections.
›What is the Ampicillin dose for dogs?
For dogs, Ampicillin is typically dosed as follows — UTI / Respiratory / Soft tissue infections: 10–40 mg/kg PO/IV/IM/SC TID to QID (q6–8h). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Ampicillin dose for cats?
For cats, Ampicillin is typically dosed as follows — UTI / Respiratory / Soft tissue infections: 10–40 mg/kg PO/IV/IM/SC TID to QID (q6–8h). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Ampicillin?
Common: Diarrhoea, Nausea, Vomiting. Serious (call your vet immediately): Anaphylaxis, Superinfection, Bone marrow suppression (rare).
›Does Ampicillin need a prescription?
Yes. Ampicillin is a prescription medication and should only be administered under veterinary supervision.
›When should Ampicillin not be used?
Do not use Ampicillin if: Known penicillin/ampicillin hypersensitivity.

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 (Aminopenicillin antibiotic).

Amoxicillin
Rx
Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs)
dogcat