Clavamox for Dogs: Uses, Dosage, Side Effects & Safety Guide
Complete guide to Clavamox for dogs: FDA-approved uses, dosage by weight, side effects, drug interactions, cost, and when to call your vet.
Clavamox requires a veterinarian prescription and should only be used under direct veterinary supervision. Never administer this medication without a valid prescription tailored to your dog's specific condition, weight, and health history. The information in this guide is educational and does not replace professional veterinary advice. Always consult your veterinarian before starting, adjusting, or discontinuing any medication.
If your dog has been prescribed Clavamox, you likely have questions about what this medication does, how to administer it correctly, and what side effects to watch for. Clavamox (amoxicillin-clavulanate potassium) is one of the most commonly prescribed antibiotics in veterinary medicine, and for good reason — it covers a broad spectrum of bacterial infections with a well-established safety profile. But like any medication, it requires careful administration and monitoring to be effective and safe.
This guide covers everything you need to know about Clavamox for dogs, including exact dosage ranges, real cost expectations, drug interactions, and the red-flag symptoms that warrant an immediate call to your vet.
What Is Clavamox and How Does It Work in Dogs?
Clavamox is a brand-name combination antibiotic containing two active ingredients: amoxicillin (a beta-lactam antibiotic in the penicillin class) and clavulanate potassium (a beta-lactamase inhibitor). It is manufactured by Zoetis and is FDA-approved for use in dogs and cats. Generic equivalents, typically labeled as amoxicillin-clavulanate potassium, are also available and functionally identical.
Mechanism of Action
Amoxicillin works by inhibiting bacterial cell wall synthesis — it binds to penicillin-binding proteins (PBPs) inside the bacterial cell wall, preventing the cross-linking of peptidoglycan chains. This weakens the cell wall and causes the bacteria to rupture and die (bactericidal action).
Clavulanate potassium serves as a bodyguard. Many resistant bacteria produce an enzyme called beta-lactamase, which destroys amoxicillin before it can do its job. Clavulanate irreversibly binds to and neutralizes beta-lactamase enzymes, allowing amoxicillin to reach its target. This combination extends Clavamox's effectiveness against bacteria that would otherwise be resistant to amoxicillin alone.
According to the Merck Veterinary Manual, potentiated penicillins like Clavamox provide expanded coverage against both gram-positive and gram-negative organisms, including beta-lactamase-producing strains of Staphylococcus, E. coli, and Klebsiella.
The amoxicillin-to-clavulanate ratio in Clavamox veterinary tablets is 4:1, which differs from many human formulations. This is one reason you should never substitute a human prescription for a veterinary one — the ratios, concentrations, and dosing schedules are calibrated differently.
FDA-Approved Uses and Common Off-Label Applications
Clavamox carries FDA approval for specific canine indications, but veterinarians frequently prescribe it off-label for conditions where clinical experience and published evidence support its use. Under the Animal Medicinal Drug Use Clarification Act (AMDUCA), off-label prescribing by licensed veterinarians is legal and common.
FDA-Approved Indications for Dogs
- Skin and soft tissue infections — wounds, abscesses, cellulitis, superficial and deep pyoderma caused by susceptible Staphylococcus species, Streptococcus, and E. coli
- Periodontal (dental) infections — gingivitis and periodontal disease caused by susceptible oral anaerobes and aerobes
Common Off-Label Uses
- Urinary tract infections (UTIs) — particularly those caused by E. coli, Proteus, or Staphylococcus
- Respiratory infections — bacterial pneumonia, kennel cough secondary bacterial infections
- Ear infections (otitis externa/media) — when bacterial culture confirms susceptible organisms
- Bone infections (osteomyelitis) — as part of a broader treatment protocol
- Anal gland abscesses
- Prostate infections (prostatitis)
Your veterinarian will typically base the decision to use Clavamox on culture and sensitivity testing when possible, particularly for recurrent infections or cases that have not responded to first-line antibiotics. Empiric therapy (prescribing before culture results return) is common for straightforward skin infections but should be followed up with susceptibility data if the infection doesn't improve within 48-72 hours.
Clavamox Dosage for Dogs by Condition and Weight
The standard dosage of Clavamox for dogs is 13.75 mg/kg (6.25 mg/lb) administered orally every 12 hours. This refers to the combined amoxicillin-clavulanate dose. Your veterinarian may adjust the dose, frequency, or duration based on the severity and location of the infection, your dog's kidney function, and clinical response.
| Condition | Dose (mg/kg) | Frequency | Typical Duration |
|---|---|---|---|
| Skin & soft tissue infections | 13.75 mg/kg | Every 12 hours | 7-14 days |
| 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 (uncomplicated); 4-6 weeks (complicated) |
| Respiratory infections | 13.75-22 mg/kg | Every 12 hours | 7-21 days |
| Deep pyoderma / osteomyelitis | 22 mg/kg | Every 12 hours | 4-8 weeks (or 2 weeks beyond clinical resolution) |
Practical Dosing by Weight
Clavamox tablets for dogs come in scored, chewable sizes: 62.5 mg, 125 mg, 250 mg, and 375 mg (combined amoxicillin + clavulanate). Here is how those tablets map to common dog weights at the standard 13.75 mg/kg dose:
| Dog Weight | Dose per Administration | Tablet Size (per dose) |
|---|---|---|
| 5 lb (2.3 kg) | ~31 mg | ½ of 62.5 mg tablet |
| 10 lb (4.5 kg) | ~62.5 mg | 1 × 62.5 mg tablet |
| 20 lb (9.1 kg) | ~125 mg | 1 × 125 mg tablet |
| 40 lb (18.2 kg) | ~250 mg | 1 × 250 mg tablet |
| 60 lb (27.3 kg) | ~375 mg | 1 × 375 mg tablet |
| 80 lb (36.4 kg) | ~500 mg | 2 × 250 mg tablets |
Important: These are reference calculations at the standard dose. Your veterinarian may prescribe a higher or lower dose based on clinical judgment. Never adjust the dose without veterinary guidance — under-dosing promotes antibiotic resistance, while overdosing increases the risk of adverse effects.
How to Administer Clavamox to Your Dog
Clavamox chewable tablets are beef-flavored and designed to be palatable. Many dogs will accept them as a treat. Here are the key administration guidelines:
- With or without food: Clavamox can be given with or without food. However, if your dog experiences vomiting or nausea on an empty stomach, giving the tablet with a small meal significantly reduces GI upset. The absorption of amoxicillin-clavulanate is not significantly affected by food.
- Consistent timing: Maintain a strict 12-hour interval between doses (e.g., 8 AM and 8 PM). Consistent blood levels are essential for bactericidal effectiveness. Set phone alarms if needed.
- Complete the full course: Even if your dog appears fully recovered after 3-4 days, continue the medication for the entire prescribed duration. Stopping early allows partially resistant bacteria to survive and multiply, potentially creating a harder-to-treat infection.
- Storage: Clavamox chewable tablets should be stored at room temperature (68-77°F / 20-25°C) in their original container, away from moisture. The oral suspension form (less common for dogs but sometimes used in small breeds and puppies) must be refrigerated after reconstitution and is stable for 10 days.
💡 Pro Tip for Picky Eaters
If your dog refuses the chewable tablet, try these techniques: hide it inside a small piece of cheese, peanut butter (xylitol-free), or a pill pocket treat. You can also crush the tablet and mix it into a small amount of wet food — but ensure your dog eats the entire portion to receive the full dose. Ask your vet about the oral suspension if pill-hiding consistently fails.
Side Effects of Clavamox in Dogs
Clavamox is generally well-tolerated, but as with any antibiotic, side effects can occur. The clavulanate component is more frequently associated with gastrointestinal upset than amoxicillin alone.
| Side Effect | Estimated Frequency | Severity | What to Do |
|---|---|---|---|
| Decreased appetite | ~10-15% | Mild | Give with food; monitor |
| Vomiting | ~5-10% | Mild-Moderate | Give with food; contact vet if persistent (>2 episodes) |
| Diarrhea / soft stools | ~10-20% | Mild | Add probiotic (2 hrs apart from dose); contact vet if bloody or >3 days |
| Lethargy | ~3-5% | Mild | Monitor; usually resolves within 24-48 hrs |
| Allergic reaction (hives, facial swelling, itching) | <1% | Serious | Stop medication; contact vet immediately |
| Anaphylaxis (collapse, difficulty breathing, pale gums) | Very rare (<0.1%) | Emergency | Emergency vet immediately |
| Severe watery/bloody diarrhea (suspected C. difficile) | Rare | Serious | Stop medication; contact vet immediately |
🚨 When to Call Your Veterinarian Immediately
Contact your vet or an emergency veterinary clinic right away if your dog exhibits any of the following while on Clavamox:
- Facial swelling, hives, or intense itching (signs of allergic reaction)
- Difficulty breathing, wheezing, or collapse
- Persistent vomiting (more than 2 episodes in 24 hours)
- Bloody or severely watery diarrhea
- Complete refusal to eat for more than 24 hours
- Yellowing of the gums or whites of the eyes (jaundice — rare but possible hepatotoxicity)
- Seizures (extremely rare, associated with very high doses or renal impairment)
If you suspect a severe adverse reaction, you can also contact the ASPCA Animal Poison Control Center at (888) 426-4435 (24/7, consultation fee applies) for guidance.
How Long Does My Dog Need to Be on Clavamox?
Treatment duration depends entirely on the type and severity of the infection. A general veterinary principle is to continue antibiotics for at least 7 days, or 2-3 days beyond complete clinical resolution — whichever is longer. Here is what to expect:
- Simple skin infections: 7-14 days
- Dental infections: 7-10 days (often paired with a dental cleaning procedure)
- Uncomplicated UTIs: 7-14 days (though current ISCAID guidelines increasingly recommend shorter 3-5 day courses for first-time, uncomplicated UTIs with other first-line drugs)
- Deep pyoderma: 4-8 weeks, often continuing 2 weeks past apparent resolution
- Osteomyelitis (bone infection): 6-8 weeks minimum
- Prostatitis: 4-6 weeks
You should see noticeable improvement within 48-72 hours of starting Clavamox. If your dog's symptoms have not improved after 3 full days of treatment, contact your veterinarian — the organism may be resistant, or the diagnosis may need reassessment. Your vet may recommend a bacterial culture and sensitivity test to identify the specific pathogen and determine which antibiotics will be most effective.
Contraindications and Drug Interactions
Clavamox is not appropriate for every dog. Understanding contraindications and drug interactions helps you have a more informed conversation with your veterinarian.
Contraindications — Dogs Who Should NOT Receive Clavamox
- Known penicillin or cephalosporin allergy: Dogs with a documented hypersensitivity to any beta-lactam antibiotic should not receive Clavamox. Cross-reactivity between penicillins and cephalosporins occurs in approximately 1-3% of cases.
- History of Clavamox-associated liver injury: Amoxicillin-clavulanate has been associated with idiosyncratic hepatotoxicity in rare cases. Dogs with a prior episode should avoid this drug.
- Severe renal impairment: Amoxicillin is primarily excreted by the kidneys. Dogs with advanced kidney disease may require dose adjustments or an alternative antibiotic. Your veterinarian will assess kidney function (BUN, creatinine, SDMA) before prescribing if renal disease is suspected.
- Rabbits, guinea pigs, hamsters, and other small herbivores: While not relevant to dogs, be aware that Clavamox is highly toxic to many small herbivorous pets in the household — never administer to these species.
Drug Interactions
| Medication / Supplement | Interaction Type | Clinical Significance |
|---|---|---|
| Bacteriostatic antibiotics (tetracyclines, chloramphenicol, macrolides) | Antagonistic — bacteriostatic drugs may reduce the bactericidal effectiveness of amoxicillin | Moderate — avoid concurrent use when possible |
| Methotrexate | Penicillins reduce renal clearance of methotrexate, increasing toxicity risk | High — requires close monitoring if concurrent use is necessary |
| Probenecid | Blocks renal tubular secretion of amoxicillin, increasing blood levels and half-life | Moderate — may be used intentionally to boost levels |
| Allopurinol | Increased risk of skin rash when combined with amoxicillin (documented in humans; relevance to dogs is extrapolated) | Low-Moderate — monitor for dermatologic reactions |
| Oral bacterins / live vaccines | Antibiotics may reduce efficacy of live bacterial vaccines (e.g., Bordetella intranasal) | Low — consider timing vaccines away from antibiotic courses |
| Probiotics | Antibiotics kill probiotic bacteria, reducing their benefit | Low — administer probiotics at least 2 hours apart from Clavamox doses |
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, heartworm medications, joint supplements, and any herbal remedies.
Monitoring Requirements and Follow-Up
For a standard short course of Clavamox (7-14 days) in an otherwise healthy dog, extensive monitoring is usually not required. However, your veterinarian may recommend the following depending on the clinical scenario:
Typical Monitoring Protocol
| Timepoint | Action |
|---|---|
| Day 0 (initiation) | Physical exam, weight measurement for accurate dosing; baseline blood work (CBC, chemistry panel) if infection is severe or dog has pre-existing conditions |
| Day 3 (48-72 hr check) | Assess clinical response — improvement expected; if no improvement, culture & sensitivity testing or imaging may be recommended |
| End of course | Recheck exam to confirm resolution; for deep infections, may extend treatment |
| Long-term courses (4+ weeks) | Periodic CBC and chemistry panel every 2-4 weeks to monitor liver and kidney function; recheck culture if applicable |
For dogs on extended Clavamox therapy (beyond 3-4 weeks), your veterinarian will likely recommend periodic blood work to monitor hepatic enzymes (ALT, ALP) and renal values, since prolonged antibiotic use places metabolic demands on the liver and kidneys.
Cost of Clavamox for Dogs and Generic Availability
Clavamox is widely available as a generic (amoxicillin-clavulanate potassium), which keeps costs relatively affordable compared to newer veterinary antibiotics.
| Form | Brand (Clavamox) | Generic Equivalent |
|---|---|---|
| 62.5 mg chewable tablets (per tablet) | $2.50 - $4.00 | $1.25 - $2.50 |
| 125 mg chewable tablets (per tablet) | $3.00 - $5.00 | $1.75 - $3.50 |
| 250 mg chewable tablets (per tablet) | $4.00 - $6.50 | $2.50 - $4.50 |
| 375 mg chewable tablets (per tablet) | $5.00 - $8.00 | $3.50 - $6.00 |
| Oral suspension 62.5 mg/mL (15 mL bottle) | $25 - $40 | $18 - $30 |
Typical total course cost: For a 40 lb dog on a 10-day course (250 mg twice daily = 20 tablets), expect to pay approximately $50-$130 for brand name or $35-$90 for generic through your veterinarian. Online veterinary pharmacies (VetRxDirect, Chewy Pharmacy, 1-800-PetMeds) may offer lower prices with your vet's authorization. Always ensure online pharmacies are NABP-accredited or VIPPS-certified to avoid counterfeit medications.
Prices vary significantly by region, pharmacy, and whether your veterinary clinic marks up dispensing fees. Some clinics include a $5-$15 dispensing fee per prescription.
Missed Doses and Overdose: What to Do
If You Miss a Dose
- Give the missed dose as soon as you remember — unless it is close to the time for the next scheduled dose.
- If it is within 2-3 hours of the next dose, skip the missed dose and resume the regular schedule.
- Never double the dose to make up for a missed one. Doubling increases the risk of vomiting, diarrhea, and other adverse effects.
- Missing a single dose is unlikely to compromise treatment, but consistently missed doses reduce effectiveness and promote antibiotic resistance.
If an Overdose Occurs
Amoxicillin-clavulanate has a wide safety margin, and a single extra dose is unlikely to cause serious harm in most dogs. However, significant overdoses (2-3× the prescribed amount or more) can cause:
- Severe vomiting and diarrhea
- Dehydration from fluid loss
- In extreme cases, crystal formation in the urine (amoxicillin crystalluria) or neurotoxicity (seizures) — particularly in dogs with impaired kidney function
🚨 Overdose Action Plan
- Assess the amount ingested — count remaining tablets and estimate how many were consumed.
- Contact your veterinarian or emergency vet clinic immediately with the estimated amount and your dog's weight.
- Call ASPCA Animal Poison Control at (888) 426-4435 (available 24/7; a consultation fee of approximately $95 applies) if your vet is unavailable.
- Do not induce vomiting unless specifically instructed by a veterinary professional.
- Monitor your dog closely for vomiting, diarrhea, lethargy, disorientation, or seizures while awaiting professional guidance.
Are There Alternatives to Clavamox for Dogs?
Yes. Your veterinarian may recommend a different antibiotic based on culture results, allergy history, cost considerations, or the specific infection site. Common alternatives include:
| Alternative Antibiotic | Drug Class | When It's Preferred | Typical Cost (per dose) |
|---|---|---|---|
| Cephalexin | 1st-gen cephalosporin | Skin infections; good first-line for uncomplicated pyoderma | $0.50 - $2.00 |
| Enrofloxacin (Baytril) | Fluoroquinolone | Gram-negative infections, UTIs, prostatitis; reserved per ISCAID guidelines | $2.00 - $5.00 |
| Doxycycline | Tetracycline | Tick-borne diseases, respiratory infections, leptospirosis | $0.75 - $2.50 |
| Metronidazole | Nitroimidazole | Anaerobic infections, Giardia, certain GI infections | $0.50 - $1.50 |
| Trimethoprim-sulfamethoxazole (TMS) | Potentiated sulfonamide | UTIs, respiratory, some skin infections; broad-spectrum, inexpensive | $0.30 - $1.00 |
The choice of antibiotic should always be guided by culture and sensitivity results when feasible. The International Society for Companion Animal Infectious Diseases (ISCAID) publishes antimicrobial use guidelines that many veterinarians follow to ensure responsible prescribing and minimize the development of resistance.
Frequently Asked Questions About Clavamox for Dogs
Can I give my dog human amoxicillin-clavulanate (Augmentin)?
No. While the active ingredients are the same, human Augmentin formulations have different amoxicillin-to-clavulanate ratios (commonly 2:1, 4:1, or 7:1 depending on the product), different tablet strengths, and different inactive ingredients that may not be safe for dogs. The veterinary-specific Clavamox formulation (4:1 ratio) is calibrated for canine pharmacokinetics. Additionally, administering a human prescription to an animal without veterinary oversight is unsafe and potentially illegal. Always use the veterinary-prescribed product.
Can Clavamox be used for ear infections in dogs?
Clavamox may be prescribed as a systemic (oral) antibiotic for ear infections, but only when bacterial culture confirms susceptible organisms and the infection involves the middle ear or has spread beyond the ear canal. Most cases of otitis externa (outer ear infection) are treated more effectively with topical ear medications that deliver a much higher concentration of antibiotic directly to the site. Many canine ear infections involve yeast (Malassezia), which Clavamox does not treat.
Will Clavamox treat my dog's kennel cough?
Most cases of kennel cough (infectious tracheobronchitis) are viral or self-limiting and do not require antibiotics. When a secondary bacterial infection is suspected or confirmed, your veterinarian may prescribe Clavamox or doxycycline. However, the AVMA's antimicrobial stewardship guidelines recommend against routine antibiotic use for uncomplicated kennel cough.
Should I give my dog probiotics while on Clavamox?
Many veterinarians recommend a canine-specific probiotic during and after antibiotic courses to help maintain healthy gut flora and reduce antibiotic-associated diarrhea. Products containing Enterococcus faecium (such as Purina FortiFlora) or Saccharomyces boulardii are commonly recommended. Administer probiotics at least 2 hours before or after the Clavamox dose to prevent the antibiotic from killing the probiotic organisms before they reach the gut.
Can pregnant or nursing dogs take Clavamox?
Amoxicillin is generally considered safe during pregnancy in dogs (Category B in human classification — no evidence of risk in animal studies). However, the safety of the clavulanate component during canine pregnancy has not been extensively studied. Your veterinarian will weigh the risks and benefits and may opt for plain amoxicillin or another antibiotic if the dog is pregnant or nursing. Always inform your vet if your dog is pregnant, may be pregnant, or is nursing puppies.
My dog's infection came back after finishing Clavamox. What now?
Recurrent infections suggest that either the original infection was not fully resolved (insufficient duration), the organism is resistant to Clavamox, or there is an underlying condition (immune suppression, anatomical abnormality, foreign body, hormonal disease) predisposing your dog to infection. Your veterinarian will likely recommend a bacterial culture and sensitivity test, additional imaging (X-rays, ultrasound), and screening for underlying conditions such as Cushing's disease, hypothyroidism, or diabetes mellitus before prescribing another antibiotic course.
Key Takeaway: Clavamox is a reliable, broad-spectrum antibiotic with a strong safety record in dogs when used appropriately under veterinary supervision. The keys to successful treatment are accurate dosing, strict 12-hour intervals, completing the full prescribed course, and reporting any concerning side effects to your veterinarian promptly. Never share medications between pets or use leftover antibiotics from a previous illness — each infection requires its own veterinary assessment.
Jonas Cole
All our authors care for dogs every day — read more of their work on the authors page.
