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Ampicillin

PrescriptionCDSCO approved

Aminopenicillin antibiotic

Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

3 available

Interactions

1 documented

Formulations

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

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 →

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

Educational reference only

Interactions

Moderate — 1

Gentamicin

moderate

Synergistic antibacterial effect but additive nephrotoxicity risk

Management: Used intentionally for synergy against enterococci. Monitor renal function closely.

Educational reference only

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.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database

Related medicines

Other medicines in the same class (Aminopenicillin antibiotic).

Amoxicillin

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

dogcat