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Cephalexin

PrescriptionCDSCO approved

First-generation cephalosporin antibiotic

Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

4 available

Interactions

1 documented

Formulations

Mechanism of action

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

At a glance

Class

First-generation cephalosporin antibiotic

Schedule

Prescription

Storage

Store below 25°C. Reconstituted suspension: refrigerate, use within 14 days

CDSCO (India)

Vet-approved — 1985-01

Dosing

🐕

Dog

Skin infections (pyoderma)

Dose

22–30 mg/kg

Route

Frequency

BID

Max dose

1000 mg/dose; 2000 mg/day

Duration: 14-21 days (deep pyoderma: 6-8 weeks)

Urinary tract infections

Dose

22–30 mg/kg

Route

Frequency

BID-TID

Max dose

1000 mg/dose; 3000 mg/day

Duration: 10-14 days

🐈

Cat

Skin and soft tissue infections

Dose

22–30 mg/kg

Route

Frequency

BID

Max dose

500 mg/dose; 1000 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

💊

Tablet — 2

Strength

250mg

Available in India

Strength

500mg

Available in India

💊

Capsule — 1

Strength

500mg

Available in India

🧴

Suspension — 1

Strength

250mg/5mL

Available in India

Storage

Store below 25°C. Reconstituted suspension: refrigerate, use within 14 days

Safety

Absolute contraindications — do not use

Known cephalosporin hypersensitivity
Cross-reactivity with penicillins possible (~5-10%)

Use with caution

Renal impairment
Dose reduction needed in severe renal failure
Concurrent nephrotoxic drugs
Increased nephrotoxicity risk

Adverse effects

Common

Vomiting

Diarrhoea

Drooling

Serious

Anaphylaxis (rare)

Neutropenia with prolonged use

Monitoring parameters

Clinical responseGI toleranceCBC for prolonged courses

Educational reference only

Interactions

Moderate — 1

Gentamicin

moderate

Both can be nephrotoxic; cephalosporins may potentiate aminoglycoside nephrotoxicity

Management: Monitor renal function (BUN/creatinine/urine sediment). Ensure adequate hydration.

Educational reference only

Brands

International

Rilexine

Virbac

Keflex

Lilly

India

Ceff

Lupin

Sporidex

Ranbaxy

FAQs

Frequently asked questions

›What is Cephalexin?

Cephalexin is a first-generation cephalosporin antibiotic used in pets. Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs)

›What is Cephalexin used for in pets?

Cephalexin is used in veterinary medicine for: Skin infections (pyoderma); Urinary tract infections; Skin and soft tissue infections.

›What is the Cephalexin dose for dogs?

For dogs, Cephalexin is typically dosed as follows — Skin infections (pyoderma): 22–30 mg/kg PO BID; Urinary tract infections: 22–30 mg/kg PO BID-TID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Cephalexin dose for cats?

For cats, Cephalexin is typically dosed as follows — Skin and soft tissue infections: 22–30 mg/kg PO BID. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What are the side effects of Cephalexin?

Common: Vomiting, Diarrhoea, Drooling. Serious (call your vet immediately): Anaphylaxis (rare), Neutropenia with prolonged use.

›Does Cephalexin need a prescription?

Yes. Cephalexin is a prescription medication and should only be administered under veterinary supervision.

›When should Cephalexin not be used?

Do not use Cephalexin if: Known cephalosporin hypersensitivity.

Educational reference only

References

CDSCO approvals (India) — 1

Cephalexin IP (as monohydrate) + Kanamycin IP (as monosulphate)

M/s. Boehringer Ingelheim · Approved 07.03.2012

For the treatment of clinical mastitis in lactating dairy cows for bacteria susceptible to the combination of cephalexin

Source: CDSCO Veterinary Drug Approval Registry (1969–2026)

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 (First-generation cephalosporin antibiotic).

Cefazolin

Binds penicillin-binding proteins (PBPs), inhibiting bacterial cell wall synthesis; bactericidal against gram-positive cocci and some gram-negative organisms

dogcat