Clavamox vs cephalexin for dogs: antibiotics compared
Clavamox (amoxicillin and clavulanate) and cephalexin are two of the antibiotics vets prescribe most for dogs, especially for skin infections. Both are given twice a day; your vet chooses based on the infection, and sometimes on a culture.
Updated October 4, 2026
At a glance
- Antibiotic family
- Clavamox
- Penicillin with a beta-lactamase blocker
- Cephalexin
- First-generation cephalosporin
- Common uses
- Clavamox
- Skin, wound, dental and urinary infections
- Cephalexin
- Skin infections, some urinary and bone infections
- How often
- Clavamox
- Twice a day
- Cephalexin
- Twice a day
- Cats
- Clavamox
- Approved for cats too
- Cephalexin
- Used in cats with vet direction
- Where to fill
- Clavamox
- Usually through your vet
- Cephalexin
- A regular pharmacy can fill human cephalexin
Clavamox amoxicillin and clavulanate | Cephalexin | |
|---|---|---|
| Antibiotic family | Penicillin with a beta-lactamase blocker | First-generation cephalosporin |
| Common uses | Skin, wound, dental and urinary infections | Skin infections, some urinary and bone infections |
| How often | Twice a day | Twice a day |
| Cats | Approved for cats too | Used in cats with vet direction |
| Where to fill | Usually through your vet | A regular pharmacy can fill human cephalexin |
Choosing the antibiotic
Both cover the staph bacteria behind most skin infections in dogs. Clavamox’s added clavulanate protects amoxicillin from bacteria that would otherwise break it down, which helps with wounds, abscesses and dental infections. For infections that keep returning, a culture shows which antibiotic will work.
Giving them
Giving either with food reduces stomach upset. Clavamox liquid is kept in the refrigerator and discarded after the period on the label; tablets come in blister packs to keep them dry. Finish the full course even if your dog seems better.
Side effects
Both commonly cause vomiting, diarrhea or reduced appetite. Stop and call your vet for hives, facial swelling or breathing trouble, or for severe or bloody diarrhea.
Skin infection care
Skin infections often follow allergies or other skin problems, so treating the underlying cause, and sometimes medicated shampoos, helps prevent the next one.
Cost
Human cephalexin capsules are inexpensive and can be filled at a regular pharmacy with your vet’s prescription. Clavamox usually comes through your vet, though generic amoxicillin and clavulanate may be an option. When filling a human prescription, ask the pharmacist to confirm the capsule strength matches your vet’s instructions.
Missed doses and leftovers
Give a missed dose as soon as you remember unless the next one is near, and never double up. Ask your vet whether a probiotic would help with antibiotic-related diarrhea, and do not save leftover antibiotics for another time; dispose of them safely.
Questions for your vet
- Which antibiotic suits this infection?
- Should a culture be done?
- What is causing the infection, and how do we prevent the next one?
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Sources
Written by the Script Unlock editorial team from the sources above. It is general information, not advice for you or your pet; your vet decides which medicine is right.
Script Unlock is a marketplace that lets licensed pharmacies quote a cash price on your prescription. It does not prescribe, dispense or sell medication, does not process patient payments, and does not give medical advice. Always follow the instructions of your prescriber and pharmacist and read the medication guide supplied with your medicine.