Complete Dosage, Safety & Side Effect Guide
Complete guide to amoxicillin clavulanate for dogs: dosage by weight, uses, side effects, drug interactions, and cost. Vet-reviewed safety info.
If your veterinarian prescribed amoxicillin clavulanate for your dog, you likely have questions about what it does, what side effects to watch for, and how to administer it correctly. Known by the brand name Clavamox® in veterinary medicine (and Augmentin® in human formulations), this combination antibiotic is one of the most commonly dispensed drugs in veterinary practice — and for good reason. It covers a broad spectrum of bacterial infections that affect dogs.
This guide breaks down everything you need to know about amoxicillin clavulanate for dogs, from mechanism of action to real cost expectations, so you can feel confident managing your dog's treatment at home.
What Is Amoxicillin Clavulanate and How Does It Work in Dogs?
Amoxicillin clavulanate (also written as amoxicillin-clavulanic acid or amoxicillin/clavulanate potassium) is a potentiated aminopenicillin antibiotic. It combines two active ingredients:
Mechanism of Action Explained
Amoxicillin (the antibiotic): A beta-lactam antibiotic in the penicillin family. It works by binding to penicillin-binding proteins (PBPs) on the bacterial cell wall, blocking peptidoglycan cross-linking. This weakens the cell wall and causes bacterial lysis — essentially, the bacteria burst and die. Amoxicillin is bactericidal (kills bacteria directly) rather than bacteriostatic (merely slowing growth).
Clavulanic acid (the potentiator): Many bacteria have evolved resistance to penicillin-family antibiotics by producing an enzyme called beta-lactamase (also known as penicillinase). This enzyme breaks the beta-lactam ring in amoxicillin's molecular structure, rendering it useless. Clavulanic acid acts as a "suicide inhibitor" — it irreversibly binds to beta-lactamase enzymes, neutralizing them before they can destroy the amoxicillin. This restores amoxicillin's effectiveness against resistant bacterial strains.
The result: A combination drug effective against both standard susceptible bacteria AND beta-lactamase-producing resistant strains, which is why your vet chose this over plain amoxicillin.
Drug class: Aminopenicillin + beta-lactamase inhibitor combination. According to the Merck Veterinary Manual, potentiated penicillins like amoxicillin clavulanate provide expanded gram-negative and anaerobic coverage compared to amoxicillin alone.
FDA-Approved and Common Off-Label Uses in Dogs
Clavamox® (the FDA-approved veterinary formulation by Zoetis) carries labeled indications for specific conditions in dogs. However, veterinarians frequently prescribe it for additional infections based on clinical judgment and culture results — this is standard and legal under the Animal Medicinal Drug Use Clarification Act (AMDUCA).
FDA-Approved Indications for Dogs
- Skin and soft tissue infections: Wound infections, abscesses, cellulitis, pyoderma (superficial and deep)
- Periodontal (dental) infections: Gingivitis, periodontitis, tooth root abscesses
Common Off-Label (Extra-Label) Uses
- Urinary tract infections (UTIs): Uncomplicated bacterial cystitis, particularly when E. coli, Proteus, or Staphylococcus are suspected
- Respiratory tract infections: Bacterial pneumonia (as part of a broader treatment protocol), tracheobronchitis
- Otitis externa/media: Ear infections with bacterial component (often combined with topical therapy)
- Osteomyelitis: Bone infections (typically at higher doses and longer durations)
- Anal gland abscesses: Post-drainage infection management
- Prophylactic use: Pre- or post-surgical infection prevention in certain procedures
Your veterinarian should ideally perform a bacterial culture and sensitivity (C&S) test before prescribing, especially for recurrent infections. This lab test identifies the specific bacteria present and confirms whether amoxicillin clavulanate will be effective against it. A C&S test typically costs $80–$180 depending on the lab.
Amoxicillin Clavulanate Dosage for Dogs by Weight and Condition
The standard veterinary formulation (Clavamox®) comes in a 5:1 ratio of amoxicillin to clavulanic acid. Available tablet strengths include 62.5 mg, 125 mg, 250 mg, and 375 mg (total combined weight). An oral suspension (62.5 mg/mL) is also available for small dogs or dogs that resist pill administration.
Important: Your veterinarian will determine the exact dose based on your dog's weight, the type and severity of infection, kidney function, and concurrent health conditions. The table below represents typical published dosage ranges — never adjust your dog's dose without veterinary approval.
| Condition | Dosage (mg/kg) | Frequency | Typical Duration |
|---|---|---|---|
| Skin/soft tissue infections | 13.75 mg/kg | Every 12 hours | 7–14 days (up to 21 for deep pyoderma) |
| Dental/periodontal infections | 13.75 mg/kg | Every 12 hours | 7–10 days |
| Urinary tract infections | 13.75–22 mg/kg | Every 12 hours | 7–14 days (up to 28 for complicated UTI) |
| Respiratory infections | 13.75–22 mg/kg | Every 12 hours | 10–21 days |
| Bone infections (osteomyelitis) | 22 mg/kg | Every 12 hours | 28–42+ days (minimum 4 weeks) |
Practical Dosing Examples by Dog Weight
Using the standard skin/soft tissue dose of 13.75 mg/kg every 12 hours:
| Dog Weight | Per-Dose Amount | Typical Tablet Prescribed |
|---|---|---|
| 10 lb (4.5 kg) | ~62 mg | 62.5 mg tablet |
| 20 lb (9 kg) | ~124 mg | 125 mg tablet |
| 40 lb (18 kg) | ~248 mg | 250 mg tablet |
| 60 lb (27 kg) | ~371 mg | 375 mg tablet |
| 80 lb (36 kg) | ~495 mg | 250 mg + 250 mg tablets |
How to Administer Amoxicillin Clavulanate to Your Dog
Correct administration directly affects whether the antibiotic reaches therapeutic blood levels. Here is what you need to know:
With or Without Food?
Amoxicillin clavulanate can be given with or without food, but giving it with a small meal significantly reduces the likelihood of gastrointestinal upset (vomiting, diarrhea, nausea). Since GI side effects are the most common complaint, most veterinarians recommend administering it alongside your dog's regular meal.
Oral Suspension Tips
- Shake well before each dose — the clavulanate component settles
- Reconstituted suspension must be refrigerated and is stable for 10 days — discard any unused portion after this period
- Use an oral syringe (not a kitchen spoon) for accurate measurement
- Direct the syringe toward the inside of the cheek, not the back of the throat, to prevent aspiration
Tablet Administration
- Clavamox® chewable tablets are beef-flavored and accepted readily by most dogs — many will eat them directly from your hand
- Standard film-coated tablets can be hidden in a small amount of canned food, peanut butter (xylitol-free), or a commercial pill pocket
- Do not crush or split tablets unless your veterinarian specifically instructs it — altering the formulation can affect absorption
Duration: How Long Does My Dog Need to Be on It?
This is one of the most important aspects of antibiotic therapy. Always complete the full prescribed course, even if your dog appears fully recovered within a few days. Stopping early selects for partially-resistant bacteria and can cause the infection to return in a harder-to-treat form.
General duration guidelines: most soft tissue infections require 7–14 days; UTIs typically require 7–14 days (complicated cases up to 28); bone infections require a minimum of 28 days. Your vet may schedule a recheck appointment to confirm resolution before authorizing discontinuation.
Side Effects of Amoxicillin Clavulanate in Dogs
Most dogs tolerate amoxicillin clavulanate well. The clavulanic acid component is responsible for a higher rate of GI effects compared to plain amoxicillin. Side effects fall into two categories: common/manageable and serious/requiring immediate intervention.
| Side Effect | Estimated Frequency | Management |
|---|---|---|
| Decreased appetite | ~15–20% | Give with food; usually resolves within 1–2 days |
| Vomiting | ~10–15% | Give with a full meal; contact vet if vomiting persists >24 hours |
| Diarrhea / soft stools | ~10–20% | Add plain canned pumpkin (1–2 Tbsp); probiotic supplement may help |
| Nausea / drooling | ~5–8% | Usually transient; administer with food |
| Allergic reaction (hives, facial swelling) | <2% | STOP medication — contact vet immediately |
| Anaphylaxis (collapse, difficulty breathing) | <0.1% | EMERGENCY — immediate veterinary care required |
- Facial swelling, hives, or intense itching (signs of drug allergy)
- Difficulty breathing, wheezing, or collapse (anaphylaxis — go to emergency vet)
- Vomiting that persists more than 24 hours or prevents keeping doses down
- Bloody or watery diarrhea lasting more than 48 hours
- Yellowing of the gums or whites of the eyes (possible hepatotoxicity)
- Seizures or unusual neurological signs
- Significant decrease in urination (possible renal impact)
Dogs with a known penicillin allergy should never receive amoxicillin clavulanate. If your dog has previously reacted to any penicillin-family drug (ampicillin, amoxicillin, penicillin G), inform your veterinarian — cross-reactivity is expected. According to ASPCA Animal Poison Control, accidental double-dosing of amoxicillin clavulanate rarely causes life-threatening toxicity but may produce significant GI distress; contact your vet or the ASPCA hotline at (888) 426-4435 if a substantial overdose occurs.
Contraindications and Drug Interactions
Not every dog is a candidate for amoxicillin clavulanate. The following contraindications and interactions should be discussed with your veterinarian before starting therapy.
Dogs Who Should NOT Receive Amoxicillin Clavulanate
- Known penicillin or cephalosporin allergy: Cross-sensitivity between beta-lactam antibiotics is well documented. Approximately 5–10% of penicillin-allergic patients also react to cephalosporins.
- History of amoxicillin clavulanate–induced hepatotoxicity: Though rare, clavulanate-associated liver injury has been reported. Dogs with a prior episode should receive an alternative antibiotic class.
- Severe renal impairment (without dose adjustment): Amoxicillin is primarily excreted by the kidneys. Dogs with IRIS Stage 3–4 chronic kidney disease may require dose reduction or extended dosing intervals.
- Small herbivores (rabbits, guinea pigs, hamsters): While irrelevant to dog owners, this drug can be fatal to these species due to fatal dysbiosis — never share your dog's medication with other pets.
Drug Interactions
| Concurrent Medication | Interaction | Clinical Significance |
|---|---|---|
| Bacteriostatic antibiotics (tetracyclines, chloramphenicol, macrolides) | May reduce amoxicillin efficacy — bactericidal drugs require actively dividing bacteria to work | Moderate — avoid concurrent use unless directed by vet |
| Methotrexate | Amoxicillin reduces renal clearance of methotrexate, increasing toxicity risk | High — requires close monitoring or alternative antibiotic |
| Probenecid | Blocks renal tubular secretion of amoxicillin, increasing blood levels | Moderate — sometimes used intentionally to extend drug levels |
| Oral bactericidal vaccines (e.g., intranasal bordetella) | Antibiotics may inactivate live bacterial vaccines | Moderate — separate vaccine and antibiotic course by at least 7 days |
| Mycophenolate mofetil | Amoxicillin clavulanate may reduce enterohepatic recirculation of active metabolite | Moderate — monitor immunosuppressive efficacy |
Always provide your veterinarian with a complete list of every medication, supplement, and over-the-counter product your dog is currently receiving. This includes flea/tick preventives, joint supplements, and any herbal remedies.
Monitoring Requirements and Follow-Up Care
For a standard 7–14 day course treating an uncomplicated skin or dental infection in an otherwise healthy dog, extensive monitoring is usually unnecessary. Your vet may schedule a brief recheck to confirm the infection has resolved. However, certain situations warrant more structured monitoring:
Baseline and Ongoing Monitoring Schedule
- Pre-treatment (before starting):
- Bacterial culture and sensitivity — especially for recurrent infections, UTIs, or post-surgical infections ($80–$180)
- Baseline blood chemistry panel if the dog has pre-existing kidney or liver disease ($80–$200)
- Mid-treatment (day 5–7 for courses longer than 14 days):
- Owner assessment: Is the infection visibly improving? Are side effects manageable?
- Veterinary check-in (often by phone/telehealth) to confirm response trajectory
- Post-treatment (within 7 days of completing course):
- Physical recheck examination ($50–$85 office visit fee)
- For UTIs: urinalysis and potentially a repeat urine culture to confirm bacterial clearance ($45–$150)
- For deep pyoderma or osteomyelitis: follow-up imaging or cytology as indicated
- Long-term courses (28+ days for bone infections):
- Repeat chemistry panel every 2–3 weeks to monitor liver enzymes and kidney values
- Assess for secondary yeast overgrowth or C. difficile–associated diarrhea
Cost, Availability, and Generic Options
Amoxicillin clavulanate is one of the more affordable veterinary antibiotics, particularly when using generic equivalents.
| Product | Form | Approximate Cost Range |
|---|---|---|
| Clavamox® (brand, Zoetis) | Chewable tablets (per tablet) | $3.50–$7.00 per tablet depending on strength |
| Generic amoxicillin/clavulanate | Film-coated tablets (per tablet) | $1.50–$4.00 per tablet |
| Clavamox® oral suspension | 15 mL bottle (reconstituted) | $25–$45 per bottle |
| Human generic Augmentin® (with vet authorization) | Tablets (via human pharmacy) | $10–$30 for a typical course with GoodRx coupon |
Cost-saving tip: Ask your veterinarian if they can write a prescription you can fill at a human pharmacy (such as Costco, Walmart, or through an online pharmacy like Chewy Pharmacy or 1-800-PetMeds). Human generic amoxicillin/clavulanate potassium is pharmacologically equivalent and often significantly cheaper than the veterinary-branded product, especially for large dogs requiring high doses. Your vet must provide the prescription — they cannot be compelled to do so, but most are willing when appropriate.
Average Total Treatment Cost by Scenario
- Simple skin infection, 20 lb dog, 10-day course (generic): $30–$60 for medication + $55–$85 office visit = $85–$145 total
- UTI, 50 lb dog, 14-day course (generic) with culture: $50–$90 medication + $100–$180 culture + $55–$85 visit = $205–$355 total
- Osteomyelitis, 60 lb dog, 42-day course (brand): $500–$900 medication + multiple rechecks + imaging = $800–$1,500+ total
Missed Doses and Overdose: What to Do
If You Miss a Dose
Give the missed dose as soon as you remember — unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular 12-hour schedule. Never double the dose to make up for a missed one. Doubling increases the risk of GI side effects and does not improve therapeutic outcomes.
Because amoxicillin clavulanate is a time-dependent antibiotic (its effectiveness depends on maintaining blood levels above the minimum inhibitory concentration for a sufficient percentage of the dosing interval), frequent missed doses can compromise treatment success. If you are consistently struggling with administration, tell your veterinarian — they may be able to switch to a once-daily alternative or a long-acting injectable antibiotic like cefovecin (Convenia®).
If an Overdose Occurs
Amoxicillin clavulanate has a relatively wide safety margin in dogs. An accidental extra dose is unlikely to cause serious harm in a healthy dog but may produce vomiting, diarrhea, or decreased appetite. However, massive overdoses (particularly in small dogs or dogs with kidney impairment) can cause crystalluria (crystal formation in urine) or neurotoxicity at extreme doses.
- Determine how much was ingested and when (check the pill bottle count)
- Call your veterinarian or emergency vet clinic immediately
- Call ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee of approximately $95 applies)
- Do NOT induce vomiting unless specifically instructed by a veterinary professional
- Bring the medication packaging to the vet visit for accurate dose calculation
Alternatives to Amoxicillin Clavulanate for Dogs
If your dog cannot tolerate amoxicillin clavulanate, has a penicillin allergy, or the infecting organism is resistant, your veterinarian may consider these alternatives:
- Cephalexin (Simplicef®): A first-generation cephalosporin commonly used for skin infections. Similar spectrum to amoxicillin but without the clavulanate component. Note: cross-reactivity risk in penicillin-allergic dogs is approximately 5–10%.
- Cefovecin (Convenia®): A long-acting injectable cephalosporin that provides 14 days of therapeutic levels from a single subcutaneous injection. Excellent option for dogs that resist oral medication. Cost: $60–$150 per injection depending on dog size.
- Doxycycline: A tetracycline-class antibiotic effective against atypical organisms (tick-borne diseases, Bordetella, Mycoplasma). Not a direct spectrum replacement — used when specific organisms are identified.
- Enrofloxacin (Baytril®): A fluoroquinolone reserved for gram-negative infections resistant to first-line drugs. Not used in growing dogs (under 8–12 months) due to risk of cartilage damage in developing joints.
- Chloramphenicol: A broad-spectrum option for deep or resistant infections. Requires careful monitoring due to potential bone marrow suppression. Owner handling precautions apply (wear gloves).
The best antibiotic is always the one confirmed effective by culture and sensitivity testing. Empirical selection (choosing without a culture) is appropriate for first-time, uncomplicated infections but should not be repeated for recurrent cases.
Frequently Asked Questions
Can I give my dog human Augmentin® instead of Clavamox®?
Human Augmentin® contains the same active ingredients (amoxicillin and clavulanate potassium) and can be used in dogs when prescribed by your veterinarian. However, the tablet strengths differ from veterinary formulations, and some human formulations contain different ratios or inactive ingredients. Your vet must calculate the correct dose and provide a written prescription. Never substitute human medication on your own — incorrect dosing can lead to treatment failure or toxicity.
How quickly will amoxicillin clavulanate start working?
Most dogs show noticeable improvement within 48–72 hours of starting the medication. Skin infections may begin to look less red and swollen; dogs with UTIs typically show reduced straining and frequency within 2–3 days. If you see no improvement after 72 hours of consistent dosing, contact your veterinarian — the bacteria may be resistant, or the diagnosis may need re-evaluation.
Can amoxicillin clavulanate cause yeast infections in dogs?
Yes. Broad-spectrum antibiotics disrupt normal skin and gut flora, which can allow Malassezia (skin yeast) or Candida (GI yeast) to overgrow. Signs include increased itching, greasy skin, a musty odor, or recurrent ear infections during or after antibiotic therapy. Your vet may recommend a concurrent antifungal shampoo or an oral probiotic to help maintain healthy microbial balance.
Is amoxicillin clavulanate safe for pregnant or nursing dogs?
Amoxicillin is generally considered safe during pregnancy (Category B in human medicine, indicating no evidence of risk in animal studies). However, clavulanate has less pregnancy safety data. Your veterinarian will weigh the risk of untreated infection against any theoretical drug risk. Always inform your vet if your dog is pregnant, may be pregnant, or is nursing puppies.
My dog's infection looks better after 4 days. Can I stop the antibiotic early?
No. Visible improvement does not mean all bacteria have been eliminated. Stopping early leaves partially-resistant organisms that can cause a relapse — and the recurring infection is often harder to treat because the surviving bacteria have been selected for resistance. Complete the entire prescribed course. If you are concerned about side effects or want to discuss early discontinuation, consult your veterinarian first.
Can I use leftover amoxicillin clavulanate from a previous prescription?
This is strongly discouraged. The leftover medication may be expired (oral suspensions expire 10 days after reconstitution; tablets typically have a 1–2 year shelf life). More importantly, the current infection may involve different bacteria requiring a different drug or dose. Using leftover antibiotics without veterinary guidance is one of the primary drivers of antimicrobial resistance. Schedule a visit and let your vet make the call.
This article is intended for educational purposes and does not replace professional veterinary advice. Always consult your veterinarian before starting, stopping, or modifying any medication regimen for your dog. For authoritative drug information, refer to the Merck Veterinary Manual and the FDA Center for Veterinary Medicine.
Dr. Hannah Wickes
All our authors care for dogs every day — read more of their work on the authors page.
