Amoxicillin-Clavulanate (Clavamox) for Cats: Uses & Dosage

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Amoxicillin-clavulanate is a prescription antibiotic combination used in cats to treat certain bacterial infections. It pairs amoxicillin, a penicillin-family antibiotic, with clavulanic acid, which helps block some bacterial enzymes that would otherwise break down amoxicillin. That combination broadens the drug's activity against susceptible bacteria and can make it more useful for infections involving beta-lactamase-producing organisms.

In veterinary medicine, you will often hear this medication called Clavamox. It is available as tablets and as an oral liquid suspension. For cats, vets commonly use it for skin and soft tissue infections, especially bite-wound abscesses, and sometimes for urinary tract infections when the bacteria are expected or proven to be susceptible.

This medication does not treat viral infections, and it is not the right choice for every cat with sneezing, coughing, diarrhea, or urinary signs. Your vet may recommend an exam, cytology, culture, or urine testing first so treatment matches the likely infection rather than guessing.

Amoxicillin-clavulanate is labeled in cats for skin and soft tissue infections such as wounds, abscesses, cellulitis, and dermatitis caused by susceptible bacteria. It is also labeled for urinary tract infections (cystitis) caused by susceptible E. coli. In real-world feline practice, one of the most common reasons your vet may prescribe it is a painful cat bite abscess that has ruptured or is likely to rupture.

Your vet may also consider this medication for some dental or oral infections, infected wounds, or other bacterial problems when the likely organisms fit the drug's spectrum. VCA notes that it is sometimes used extra-label for additional infections in dogs and cats, which is common and legal in veterinary medicine when clinically appropriate.

Because not every infection responds to the same antibiotic, your vet may recommend a culture and susceptibility test, especially if your cat has a recurrent infection, a urinary infection, a deep wound, or poor response to initial treatment. That step can help avoid unnecessary antibiotic changes and supports more thoughtful antimicrobial use.

Always give amoxicillin-clavulanate exactly as your vet prescribes. Published veterinary references list common feline dosing as 62.5 mg per cat by mouth every 12 hours, and Merck also lists 10-20 mg/kg by mouth every 8 hours in some situations. The exact dose, schedule, and duration depend on your cat's weight, the infection site, severity, kidney function, and the product your vet dispenses.

For labeled feline tablet use, product information for Clavacillin lists 62.5 mg twice daily for cats. Skin and soft tissue infections are commonly treated for 5-7 days or for 48 hours after signs resolve, while urinary tract infections may need 10-14 days or longer, with treatment duration generally not exceeding 30 days unless your vet has a specific reason and monitoring plan.

This medication is usually given with food to reduce stomach upset. If you are using the liquid form, shake it well and measure carefully with the syringe or dosing device provided. Reconstituted liquid should be refrigerated and commonly discarded after 10 days based on veterinary client guidance for Clavamox-type suspensions.

If you miss a dose, give it when you remember unless it is close to the next scheduled dose. Then skip the missed dose and return to the regular schedule. Do not double up. If your cat spits out doses, vomits after dosing, or refuses the medication, contact your vet before changing the plan.

The most common side effects in cats are digestive upset, including decreased appetite, vomiting, and diarrhea. Post-approval reporting for veterinary amoxicillin-clavulanate tablets also lists anorexia, lethargy, vomiting, and diarrhea among the more commonly reported adverse events. Mild stomach upset may improve when the medication is given with food, but ongoing symptoms still deserve a call to your vet.

Less commonly, cats can have an allergic reaction. Warning signs include facial swelling, hives, rash, trouble breathing, fever, or sudden collapse. Drug sensitivities can appear even after earlier doses seemed fine, so keep watching throughout the full course.

See your vet immediately if your cat has repeated vomiting, severe diarrhea, marked lethargy, swelling of the face, breathing changes, or stops eating. Also call promptly if the infection looks worse after a few days, because that may mean the bacteria are resistant, the infection needs drainage, or another diagnosis is more likely.

Amoxicillin-clavulanate can interact with other medications, so your vet should know about every prescription, over-the-counter product, probiotic, supplement, and herbal product your cat receives. VCA lists several drugs that should be used with caution alongside amoxicillin-clavulanate, including chloramphenicol, erythromycin, tetracycline, pentoxifylline, and cephalosporins.

Some antibiotics can interfere with how bactericidal penicillin-family drugs work, while other combinations may increase the chance of side effects or complicate monitoring. Cats with a history of allergy to penicillins or cephalosporins should generally avoid this medication unless your vet determines otherwise.

Tell your vet if your cat has kidney disease, prior antibiotic reactions, chronic vomiting or diarrhea, or is taking several medications at once. That does not always mean Clavamox cannot be used. It means the plan may need dose adjustments, closer follow-up, or a different antibiotic option.