What Does Clavamox Treat in Dogs? UTIs, Ears, and Skin

Name: What Does Clavamox Treat in Dogs? UTIs, Ears, and Skin
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Clavamox for dogs uses center on bacterial infections of the urinary tract, ears, and skin. It is a prescription antibiotic that kills certain bacteria, but it does nothing for yeast, parasites, allergies, or viruses. This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Clavamox is amoxicillin combined with clavulanate, a drug that blocks bacterial enzymes called beta-lactamases that would otherwise destroy amoxicillin.
It treats susceptible bacterial infections, including some urinary tract infections, bacterial otitis externa, and bacterial skin infections.
It does not treat yeast, mites, allergies, or viral illness, which are common causes of ear and skin problems in dogs [1].
Your veterinarian should confirm the type of infection before prescribing, often with a sample for culture and sensitivity.
Give the full course exactly as prescribed, even if your dog looks better in a few days.

What Clavamox Is and What It Treats

Clavamox is a brand name for amoxicillin trihydrate combined with potassium clavulanate. Amoxicillin is a penicillin-type antibiotic that stops bacteria from building their cell walls. Clavulanate is not an antibiotic on its own. It works by disabling beta-lactamase enzymes that many bacteria produce to break down amoxicillin. Adding clavulanate widens the range of bacteria the drug can kill.

Veterinarians prescribe Clavamox for bacterial infections in several body systems. The most common reasons are skin infections, ear infections, and urinary tract infections. It may also be used for bite wounds, dental infections, and some respiratory infections, depending on the bacteria involved.

Clavamox for Dogs UTI

A urinary tract infection happens when bacteria climb into the bladder or, less often, the kidneys. The most common culprit in dogs is Escherichia coli. In one 10-year study of canine urine cultures, E. coli made up 47.5% of isolates [2].

Clavamox can be a reasonable choice for a bladder infection caused by a susceptible strain of E. coli or another susceptible bacterium. The same study found that resistance to amoxicillin-clavulanate in canine urinary pathogens fell significantly over the study period, from 52.6% to 25.6% [2]. That means roughly one in four urinary bacteria in that population was still resistant, so the drug will not work for every dog.

That is why testing matters. A urine sample collected sterilely and sent for culture and sensitivity tells your veterinarian which bacteria are present and which antibiotics will kill them. The International Society for Companion Animal Infectious Diseases recommends that treatment choices be guided by local data on which bacteria are common and which drugs they resist [2]. Your veterinarian applies the same logic to your dog's specific culture result.

Clavamox for Dogs Ear Infection

Ear infections in dogs, called otitis externa, have many possible causes. These include parasites, foreign objects, allergies, bacterial infection, yeast infection, and middle ear disease [1]. Often more than one problem is present at the same time.

Clavamox only helps when bacteria are part of the problem and those bacteria are susceptible to it. It does nothing for yeast such as Malassezia pachydermatis, which is a frequent cause of ear disease in dogs [3]. It also does nothing for mites, allergies, or a grass awn stuck in the canal.

Your veterinarian will usually look inside the ear with an otoscope and take a sample of discharge to examine under the microscope or send for culture [1]. That step separates a bacterial infection from a yeast infection or a mixed infection. If yeast is the main problem, antibiotic treatment is unnecessary and works against good antibiotic stewardship [3].

Ear infections often return unless every underlying cause is treated [1]. If your dog has recurring ear problems, ask your veterinarian about the primary trigger. Allergy is a leading cause, and managing the allergy is part of stopping the cycle. You can read more about what is the treatment for ear infection in dogs and dog itchy ears medicine for background on how veterinarians approach these cases.

Clavamox for Dogs Skin Infection

Bacterial skin infections, often called pyoderma, are another common reason Clavamox is prescribed. These infections frequently sit on top of another skin disease such as allergies, parasites, or hormonal conditions. Successful treatment of a skin disorder requires finding the underlying cause, not just killing the bacteria [4].

Clavamox can clear susceptible bacterial pyoderma, but the infection may come right back if the trigger is still present. Your veterinarian may also prescribe medicated shampoos or topical products alongside the oral antibiotic. Medicated shampoos work best on a clean coat, so wash your dog with a cleansing shampoo and rinse well before applying one [4]. Follow your veterinarian's instructions closely for any topical medication, and use ointments, gels, and sprays sparingly so your dog does not lick off too much [4].

If your dog is itchy and uncomfortable, ask your veterinarian whether a topical or other treatment should be added. More detail is available in what are the side effects of Clavamox for dogs.

How Clavamox Works

Bacteria build a protective cell wall to survive. Amoxicillin blocks the enzymes that assemble that wall, so the bacteria weaken and die. Many bacteria defend themselves by making beta-lactamase enzymes that cut amoxicillin apart before it can work. Clavulanate binds those enzymes and shuts them down, which lets amoxicillin do its job.

This is why Clavamox covers more bacteria than plain amoxicillin. It is also why Clavamox is not a treatment for organisms that lack a bacterial cell wall, such as yeast, or for problems that are not infections at all, such as allergies.

Dosing Basics

Only your veterinarian decides the dose. Clavamox dosing depends on your dog's weight, the site and severity of the infection, and your dog's kidney and liver health. Never guess a dose or borrow medication from another pet.

Clavamox comes as oral tablets and as a liquid suspension. Most dogs take it by mouth, usually two or three times a day, with or without food. Giving it with a small meal can reduce stomach upset. Shake liquid suspension well before each dose, and use the measuring device your veterinarian or pharmacy provides.

If you miss a dose, give it as soon as you remember. If it is almost time for the next dose, skip the missed one and continue on schedule. Do not double up to make up for a missed dose. Call your veterinarian if you are unsure what to do.

Finish the entire course. Stopping early because your dog seems better can let surviving bacteria regrow, and it encourages resistance.

Side Effects

Most dogs tolerate Clavamox well. When problems happen, they are usually mild and short lived. Call your veterinarian if any side effect worries you.

Side effect	How common or serious	What to do
Vomiting, diarrhea, or soft stool	Common and usually mild	Give with food, and call your veterinarian if it continues or worsens
Loss of appetite	Fairly common and usually mild	Offer small meals, and report it if your dog stops eating
Lethargy	Less common, can signal a problem	Call your veterinarian the same day
Itching, hives, or facial swelling	Uncommon but serious allergic reaction	Stop the drug and seek veterinary care right away
Difficulty breathing or collapse	Rare but an emergency	Go to an emergency clinic immediately
Yellow gums, eyes, or skin	Rare and serious, may signal liver problems	Stop the drug and contact your veterinarian immediately

If your dog has a known penicillin or cephalosporin allergy, tell your veterinarian before starting Clavamox. Watch for any new rash, swelling, or breathing change after the first dose.

Who Should Not Take It and Drug Interactions

Clavamox is not right for every dog. Tell your veterinarian about all medications, supplements, and health conditions before your dog starts the drug.

Dogs with a known allergy to penicillins or cephalosporins should not take Clavamox. Dogs with liver or kidney disease may need a different drug or a modified plan, and your veterinarian will decide based on blood work.

Some drugs can interact with Clavamox. These include certain other antibiotics, some gout medications, blood thinners, and methotrexate. Do not start or stop any medication without asking your veterinarian first.

Clavamox is not effective against yeast, parasites, or viral infections, so it will not help those problems no matter how long it is given [1][3].

Overdose and When to Call for Help

An overdose can cause severe vomiting, diarrhea, and stomach pain. In large amounts, it can lead to more serious problems. If you think your dog swallowed too much Clavamox, call your veterinarian or a pet poison helpline right away. Have the bottle with you so you can read the strength and the amount your dog may have taken.

Do not wait for symptoms to appear before you call. Early guidance can prevent a mild mistake from becoming a serious one.

Limitations and When to Contact a Veterinarian

Clavamox only works on susceptible bacteria. It will not fix a yeast infection, ear mites, a foreign object in the ear, or an allergy. It will not cure a skin problem that keeps recurring because the underlying cause was never treated [4][1]. And it will fail if the bacteria causing the infection are resistant to it, which is why culture and sensitivity testing matters for urinary, ear, and skin infections [2][5].

Contact your veterinarian the same day if your dog vomits repeatedly, refuses food, seems weak, or has diarrhea that does not improve. Go to an emergency clinic now if your dog has facial swelling, hives, trouble breathing, collapse, or yellow gums or eyes. Schedule a routine visit if symptoms are not improving after a few days of treatment, if the infection returns after the course ends, or if your dog has had repeated infections in the same spot.

Every dog is different. Your veterinarian needs to examine your pet and may need test results before deciding whether Clavamox is the right antibiotic.

Frequently Asked Questions

Can I give my dog leftover Clavamox from a previous illness?

No. Leftover antibiotics may be the wrong drug, the wrong dose, or expired, and the infection may now be caused by different bacteria. Call your veterinarian for a fresh evaluation instead.

How long does it take for Clavamox to start working in dogs?

Many dogs improve within a few days, but the full course must be finished. If your dog is not better after a few days, or gets worse, contact your veterinarian.

Can Clavamox treat a yeast infection in my dog's ear?

No. Clavamox targets bacteria only. Yeast such as Malassezia pachydermatis needs antifungal treatment, and using an antibiotic for a yeast-only infection is not appropriate [3].

Is Clavamox the same as amoxicillin?

No. Clavamox contains amoxicillin plus clavulanate, which blocks bacterial enzymes that would otherwise destroy amoxicillin. Plain amoxicillin covers fewer bacteria, and resistance to it can be high in some infections [2].

What should I do if my dog vomits after taking Clavamox?

Try giving the next dose with a small meal, and call your veterinarian if vomiting continues. Repeated vomiting, refusal to eat, or lethargy needs same-day veterinary attention.

References

Ear Infections and Otitis Externa in Dogs - Dog Owners. Merck Veterinary Manual.
Prevalence and Antimicrobial Resistance Trends of Canine Uropathogens in a Veterinary Teaching Hospital in Northern Italy: A 10-Year Retrospective Study (2014-2023). Veterinary sciences, 2025.
A Randomised Placebo-Controlled Study to Evaluate the Efficacy and Safety of a Two-Dose Topical Terbinafine and Betamethasone Gel for the Treatment of Yeast (Malassezia pachydermatis) Otitis Externa in Dogs. Veterinary dermatology, 2026.
Treatment of Skin Disorders in Dogs - Dog Owners. Merck Veterinary Manual.
Prevalence and Antimicrobial Resistance Profiles of E. coli, P. mirabilis, and E. cloacae Complex Isolated from Dogs with Otitis Externa. Antibiotics (Basel, Switzerland), 2026.