Cephalexin (Keflex®, Rilexine®) for Dogs and Cats

Cephalexin (Keflex®, Rilexine®) for Dogs and Cats

cephalexin for dogs and catscephalexin for dogs and cats
cephalexin for dogs and catscephalexin for dogs and cats

Overview of Cephalexin for Canines and Felines

  • Cephalexin, also known by the brand names Keflex® and Rilexine®, is an antibiotic used for dogs and cats. Cephalexin belongs to the cephalosporin class of drugs and is related to the penicillin drugs in how it kills bacteria. Cephalosporins have a much broader range of activity against bacteria than penicillins. Cephalexin is one of the most commonly prescribed antibiotics to dogs and cats.
  • Cephalexin will prevent the bacteria from forming an adequate and protective cell wall. This results in instability and subsequent death of the bacteria.
  • Cephalexin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.
  • This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.

Brand Names and Other Names of Cephalexin

  • This drug is registered for use in dogs and cats only.
  • Human formulations: Keflex® (Dista), and various other generic forms
  • Veterinary formulations: Rilexine®

Uses of Cephalexin for Dogs and Cats

  • Cephalexin is used in both dogs and cats to treat a variety of bacterial infections, including skin infections, wound infections, bone infections, pneumonia, and bladder infections.
  • Cephalexin is similar to the veterinary drug cefadroxil, and veterinarians often use the two drugs interchangeably. The drugs have equal effectiveness.
  • Cephalexin is not effective against infections caused by parasites (intestinal worms), mites, viruses or fungi.

Precautions and Side Effects

  • While generally safe and effective when prescribed by a veterinarian, cephalexin can cause side effects in some animals.
  • Cephalexin should not be used in animals with known hypersensitivity or allergy to the drug.
  • If a dog or cat is already sensitive to allergy or vomiting from other cephalosporin drugs (cefadroxil) or penicillins (amoxicillin, ampicillin), cross-reaction with cephalexin is possible.
  • Cephalexin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with cephalexin. Such drugs include certain other antibiotics.
  • The most common side effect in animals is vomiting shortly after administration. It is usually not a sign of serious disease but indicates that the pet is sensitive to this drug.
  • It is not unusual for some animals to develop diarrhea from orally administered antibiotics such as cephalexin. However, this has not been a common complaint with cephalexin.

How Cephalexin Is Supplied

  • Cephalexin is available in 250 mg and 500 mg capsules, 250 mg and 500 mg tablets and an oral suspension in the strength of 25 mg/ml and 50 mg/ml.
  • Cephalexin Chewable Tablets (Rilexine®): 75 mg, 150 mg, 300 mg, and 600 mg.
  • An injectable version is available in some countries.


Dosing Information of Cephalexin for Dogs and Cats

  • Medication should never be administered without first consulting your veterinarian.
  • The usual dose of cephalexin for dogs and cats is 10 to 15 mg per pound (22 to 30 mg/kg) every 8 to 12 hours orally.
  • Reduced dosages are recommended for pets with kidney failure.
  • Should be administered with food if cephalexin causes nausea or vomiting in your pet.
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.


 Antibiotics & Antimicrobial Drugs

Orthopedics & musculoskeletal diseases
Nephrology & Urology
Otic diseases
Dermatology & Integumentary diseases
Respiratory & Thoracic diseases
Multiple organ systems can be affected



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