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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
4

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
PO
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
PO
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
PO
Frequency
BID
Max dose
500 mg/dose; 1000 mg/day
Duration: 7-14 days

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

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.

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.

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

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 →

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