Before you give it: is cephalexin the right fit?
Cephalexin suits a specific set of infections. A quick check first:
- Get a diagnosis first. Skin and soft-tissue problems can look alike but need different treatment; a vet should confirm what’s going on and whether cephalexin fits.
- Skin, wound, and soft-tissue infections are its wheelhouse. Cephalexin is a common first-generation cephalosporin choice for pyoderma and related infections — not a broad “any infection” drug.
- Weigh your pet. The dose is set by body weight, so your vet needs an accurate weight to prescribe correctly.
- Mention any prior reaction. Tell your vet if your dog or cat has reacted to penicillin or cephalosporin antibiotics before.
What cephalexin for dogs and cats is
Cephalexin is a first-generation cephalosporin, a beta-lactam antibiotic,1 prescribed for dogs and cats mainly for skin infections (pyoderma), wounds, and some soft-tissue infections.2 Whether it is the right choice, and at what dose, is a decision for the prescribing veterinarian — based on the specific infection, your pet’s weight and history, and what the vet finds appropriate.
We are a licensed veterinary pharmacy. We dispense what the vet prescribes3 — we do not diagnose or set doses — and we will tell you plainly when cephalexin is not the right fit for your pet.
| Active ingredient | Cephalexin |
|---|---|
| Strength | 250 mg or 500 mg per capsule |
| Also sold as | Keflex |
| Drug class | First-generation cephalosporin (beta-lactam) |
| Form | Capsules in blister packs |
| Intended use | Dogs and cats only |
| Availability | Prescription, not for human use |
| Delivery to | All 50 US states, contact us for other countries |
Cephalexin dosing for dogs and cats: your vet sets it
Cephalexin for dogs and cats is dosed by body weight and set by your prescribing veterinarian, based on the infection, your pet’s weight, and their health history. We do not set doses, and this page does not list one. The label on your order reflects your prescribing vet’s instructions — follow it exactly and never adjust the dose yourself. Cephalexin comes in 250 mg and 500 mg capsules; which strength fits your pet is part of what the vet decides.
Side effects to watch for
Cephalexin is generally well tolerated. The most common effects are digestive — vomiting, diarrhea, or drooling — and giving it with food usually helps; some pets show a reduced appetite. Call your vet for signs of an allergic reaction (facial swelling, hives, difficulty breathing) or severe diarrhea. Tell your vet if your dog or cat has reacted to penicillin or cephalosporin antibiotics before.
⚠ Important safety notes
- Prescription medication. A veterinarian decides whether it’s appropriate and sets the dose — we never set one.
- Give it with food. This usually eases the common digestive effects (vomiting, diarrhea, drooling).
- Watch for allergic signs. Facial swelling, hives, difficulty breathing, or severe diarrhea — stop and call your vet. Mention any prior penicillin or cephalosporin reaction.
- For dogs and cats only. Keep away from people, and never dose a pet from a human or another species’ prescription.
Cost & how to get it
There is no public cart or online payment step. You place a reservation, a veterinarian reviews it and writes the prescription if it’s appropriate, then our pharmacy sends a secure payment link before anything ships — so the veterinary review costs you nothing separate, and you pay only for the medication. If cephalexin isn’t right for your dog or cat, the order isn’t filled and you aren’t charged.
| Pack size | 250 mg | 500 mg |
|---|---|---|
| 30 capsules | $39.99 · $1.33/capsule | $45.99 · $1.53/capsule |
| 90 capsules MOST POPULAR | $89.99 · $1.00/capsule | $102.99 · $1.14/capsule |
| 200 capsules | $129.99 · $0.65/capsule | $148.99 · $0.74/capsule |
| 500 capsules BEST VALUE | $199.99 · $0.40/capsule | $229.99 · $0.46/capsule |
The 500 mg capsule costs a little more than the 250 mg at each pack size — your vet sets the strength your pet needs.
Related guides
Frequently asked questions
Do I need a prescription?
Yes — but you don’t have to arrange it yourself. A veterinarian reviews your order and prescribes it, then we dispense it legally. If it’s not right for your dog or cat, the order isn’t filled and you aren’t charged.
What is cephalexin used for in dogs and cats?
It is a first-generation cephalosporin most often prescribed for skin infections (pyoderma), wounds, and some soft-tissue infections. Whether it fits your pet is the prescribing vet’s decision.
What dose should I give?
We don’t provide dosing. The correct dose depends on your pet’s weight and condition and is set by the prescribing veterinarian. Follow the prescription exactly.
Is this the same as Keflex?
Keflex is a brand name for cephalexin. This is the same active ingredient; brand and packaging may vary.
Do I get exactly what I see on this site?
We can’t guarantee a specific manufacturer. What you receive may look different, but the drug, strength, and ingredients are the same.
Medical disclaimer
This site is for informational purposes only and is not veterinary advice, diagnosis, or a treatment recommendation. A licensed veterinarian should determine medication selection, prescribing, dosing, and treatment for the individual animal. Never give a dog or cat antibiotics intended for another species; the wrong drug or dose can seriously harm your pet. All medications sold on this site are for animal use only and are not intended for human use or consumption.
Sources & References
- Merck Veterinary Manual, “Cephalosporins and Cephamycins Use in Animals.” merckvetmanual.com (accessed 2026) Supports: cephalexin is a first-generation cephalosporin (a beta-lactam antibiotic).
- Hillier A, Lloyd DH, Weese JS, et al. “Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (ISCAID).” Vet Dermatol 2014;25(3):163–175. doi:10.1111/vde.12118. doi.org (2014) Supports: first-generation cephalosporins (cephalexin) are a first-line systemic option for canine superficial bacterial folliculitis (pyoderma).
- FDA Center for Veterinary Medicine. Animal & Veterinary. fda.gov (accessed 2026) Supports: the prescription status of veterinary antibiotics.
