Antibiotics for Dogs: Clavamox Uses, Dosage, & Safety Guide
Complete guide to Clavamox antibiotics for dogs: dosage by weight, side effects, drug interactions, cost, and what conditions it treats. Vet-reviewed 2026.
Clavamox (amoxicillin/clavulanate potassium) requires a veterinarian prescription and should only be used under direct veterinary supervision. Never administer leftover antibiotics from a previous illness, share medications between pets, or adjust dosages without consulting your veterinarian. Incomplete or improper antibiotic courses contribute to antimicrobial resistance — a growing threat to both animal and human health.
What Is Clavamox and Why Do Vets Prescribe It?
Clavamox is a broad-spectrum antibiotic combination medication widely prescribed in veterinary medicine. It contains two active ingredients: amoxicillin (a penicillin-class antibiotic) and clavulanate potassium (a beta-lactamase inhibitor). Together, these compounds tackle bacterial infections that would otherwise resist standard amoxicillin treatment.
The brand name Clavamox is manufactured by Zoetis and holds FDA approval for veterinary use in dogs and cats. Generic equivalents — typically labeled as amoxicillin/clavulanate potassium tablets or chewables — are widely available and often significantly cheaper.
How Clavamox Works: Mechanism of Action
Amoxicillin attacks bacterial cell walls by binding to penicillin-binding proteins (PBPs), disrupting peptidoglycan cross-linking. Without intact cell walls, bacteria burst and die.
Clavulanate potassium acts as a bodyguard. Many resistant bacteria produce an enzyme called beta-lactamase that destroys amoxicillin before it can work. Clavulanate irreversibly binds to beta-lactamase, neutralizing it so amoxicillin can do its job.
Result: Clavamox covers a wider range of bacteria than amoxicillin alone, including beta-lactamase-producing strains of Staphylococcus, E. coli, and Pasteurella.
FDA-Approved and Common Off-Label Uses
Clavamox carries FDA approval for specific indications in dogs, but veterinarians frequently prescribe it off-label for additional conditions — a standard and legal practice in veterinary medicine when supported by clinical evidence.
| Condition | Approval Status | Typical Pathogens Targeted |
|---|---|---|
| Skin infections (pyoderma, wounds, abscesses) | FDA-approved | Staphylococcus pseudintermedius, Streptococcus spp. |
| Periodontal (dental) infections | FDA-approved | Pasteurella, anaerobic oral bacteria |
| Urinary tract infections (UTIs) | Off-label (common) | E. coli, Proteus, Klebsiella |
| Respiratory infections | Off-label (common) | Bordetella, Pasteurella |
| Ear infections (otitis externa) | Off-label (common) | Staphylococcus, Proteus |
| Anal gland abscesses | Off-label | Mixed aerobic/anaerobic flora |
| Prostate infections (prostatitis) | Off-label | E. coli, Brucella |
According to the Merck Veterinary Manual, amoxicillin-clavulanate combinations are considered first-line therapy for many soft tissue infections where culture and sensitivity results are pending. Your veterinarian will ideally collect a bacterial culture before starting treatment, especially for recurrent infections, to confirm Clavamox is the right choice.
Typical Clavamox Dosage for Dogs by Condition
Clavamox dosing depends on the infection type, severity, and your dog's weight. The standard formulation uses a 7:1 ratio of amoxicillin to clavulanate (for example, a 62.5 mg tablet contains 50 mg amoxicillin and 12.5 mg clavulanate).
| Dog Weight | 62.5 mg Tablets | 125 mg Tablets | 250 mg Tablets | 375 mg Tablets | Frequency |
|---|---|---|---|---|---|
| 5 lb (2.3 kg) | ½ tablet | — | — | — | Every 12 hrs |
| 10 lb (4.5 kg) | 1 tablet | ½ tablet | — | — | Every 12 hrs |
| 20 lb (9 kg) | 2 tablets | 1 tablet | ½ tablet | — | Every 12 hrs |
| 40 lb (18 kg) | 4 tablets | 2 tablets | 1 tablet | — | Every 12 hrs |
| 60 lb (27 kg) | — | 3 tablets | 1½ tablets | 1 tablet | Every 12 hrs |
| 80 lb (36 kg) | — | 4 tablets | 2 tablets | 1½ tablets | Every 12 hrs |
Dosage based on 6.25 mg/lb (13.75 mg/kg) of combined amoxicillin/clavulanate every 12 hours. Your veterinarian may adjust based on infection severity. Always follow your vet's exact prescription instructions.
Dosage by Condition
- Skin and soft tissue infections: 6.25 mg/lb (13.75 mg/kg) every 12 hours for 7–14 days
- Urinary tract infections: 6.25–12.5 mg/lb (13.75–27.5 mg/kg) every 12 hours for 10–14 days (often extended to 4–6 weeks for recurrent or upper UTIs/pyelonephritis)
- Dental/periodontal infections: 6.25 mg/lb (13.75 mg/kg) every 12 hours for 7–10 days, typically starting 3–5 days before a dental procedure
- Respiratory infections: 6.25–12.5 mg/lb every 12 hours for 10–21 days depending on severity
How to Administer Clavamox to Your Dog
Clavamox comes in several formulations, and how you give it matters for both effectiveness and your dog's willingness to cooperate.
Available Formulations
- Chewable tablets — beef-flavored, scored for splitting. Most dogs accept these readily as treats.
- Standard tablets — can be hidden in pill pockets, cheese, or peanut butter (xylitol-free only).
- Oral suspension (liquid) — reconstituted by your pharmacy, ideal for small dogs under 10 lb. Must be refrigerated after mixing and discarded after 10 days.
- Drops (pediatric formulation) — sometimes prescribed for very small breeds or puppies.
Administration Tips
- With or without food: Clavamox can be given with or without food. However, giving it with a small meal reduces the chance of nausea or vomiting, which occurs in roughly 10% of dogs.
- Timing consistency: Give doses at the same times each day, approximately 12 hours apart. Setting phone alarms helps maintain steady blood levels of the drug.
- Complete the full course: Even if your dog appears fully recovered after 3–4 days, finish every prescribed dose. Stopping early allows surviving bacteria to develop resistance, potentially creating a harder-to-treat infection next time.
- Liquid suspension: Shake well before each dose. Use the provided oral syringe rather than a kitchen spoon for accuracy. Store in the refrigerator.
Side Effects: What to Expect and When to Worry
Most dogs tolerate Clavamox well, but as with any antibiotic, side effects can occur. Understanding the frequency and severity helps you distinguish normal reactions from emergencies.
| Side Effect | Estimated Frequency | Severity | What to Do |
|---|---|---|---|
| Vomiting | ~10% | Mild | Give with food; contact vet if persistent |
| Diarrhea / loose stools | ~15% | Mild to moderate | Add probiotic (2 hrs apart); call vet if bloody or lasts >48 hrs |
| Decreased appetite | ~8% | Mild | Offer with favorite food; monitor |
| Drooling (bitter taste) | ~5% | Mild | Normal reaction to taste; use pill pocket |
| Allergic reaction (hives, facial swelling) | <2% | Serious | Stop medication; contact vet immediately |
| Anaphylaxis (collapse, difficulty breathing) | <0.1% | Emergency | Emergency vet immediately |
| Severe bloody diarrhea (C. difficile) | Rare | Serious | Stop medication; contact vet immediately |
🚨 Seek Immediate Veterinary Care If Your Dog Shows:
- Facial swelling, hives, or intense itching within hours of a dose
- Difficulty breathing, wheezing, or collapse
- Severe vomiting (more than 3 episodes in 24 hours)
- Bloody or black tarry diarrhea
- Seizures or uncoordinated movement
- Complete refusal to eat or drink for more than 24 hours
ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies) if accidental overdose occurs.
Antibiotic-Associated Diarrhea: A Practical Note
Clavamox disrupts normal gut bacteria along with the pathogens it targets. This frequently causes loose stools. Many veterinarians recommend a canine-specific probiotic (such as Purina FortiFlora or Proviable-DC) given at least 2 hours apart from the antibiotic dose to help maintain healthy gut flora. Do not give probiotics at the same time as Clavamox — the antibiotic will kill the beneficial bacteria in the probiotic.
How Long Does My Dog Need to Be on Clavamox?
Duration depends entirely on the infection being treated. Here are typical treatment courses based on current veterinary guidelines:
| Infection Type | Typical Duration | Notes |
|---|---|---|
| Superficial skin infection | 7–14 days | Continue 7 days past clinical resolution |
| Deep pyoderma | 3–6 weeks | May require culture-guided therapy |
| Simple UTI (first occurrence) | 7–14 days | Follow-up urinalysis recommended |
| Recurrent or complicated UTI | 4–6 weeks | Culture and sensitivity essential |
| Dental infection (pre-procedure) | 7–10 days | Start 3–5 days before dental work |
| Respiratory infection (pneumonia) | 3–6 weeks | May need additional antibiotics |
The general veterinary principle, referenced by the AVMA's antimicrobial stewardship guidelines, is to treat for the shortest effective duration while ensuring complete resolution. Your veterinarian may schedule a recheck appointment to confirm the infection has cleared before discontinuing treatment.
Contraindications: Dogs Who Should NOT Receive Clavamox
Clavamox is not appropriate for every dog. Your veterinarian will screen for these contraindications before prescribing:
- Penicillin or cephalosporin allergy: Dogs with known hypersensitivity to any penicillin-class drug should never receive Clavamox. Cross-reactivity with cephalosporins (e.g., cephalexin) occurs in approximately 5–10% of allergic patients.
- History of antibiotic-associated liver disease: Amoxicillin-clavulanate has been rarely linked to idiosyncratic hepatotoxicity (liver injury with unknown cause) in dogs. If your dog has experienced this previously, your vet will choose an alternative.
- Severe kidney disease: While not an absolute contraindication, dogs with advanced renal failure may need dose adjustments since amoxicillin is primarily excreted through the kidneys. Your vet will calculate a reduced dose based on GFR (glomerular filtration rate) estimates.
- Very young puppies: Use in puppies under 4 weeks of age requires careful veterinary judgment, as immature kidneys may not clear the drug efficiently.
- Rabbits, guinea pigs, hamsters: While not relevant to dog owners, be aware that Clavamox is contraindicated in many small herbivorous mammals due to risk of fatal enterotoxemia. Never share your dog's medication with other pets.
Drug Interactions: What Your Vet Needs to Know
Before starting Clavamox, provide your veterinarian with a complete list of every medication, supplement, and over-the-counter product your dog receives. Key interactions include:
| Drug / Supplement | Interaction Type | Clinical Significance |
|---|---|---|
| Methotrexate | Amoxicillin reduces methotrexate clearance | High — risk of methotrexate toxicity; avoid combination or monitor blood levels closely |
| Bacteriostatic antibiotics (tetracycline, chloramphenicol, erythromycin) | May antagonize bactericidal action of amoxicillin | Moderate — reduced effectiveness; vets typically avoid concurrent use |
| Probenecid | Blocks renal excretion of amoxicillin, raising blood levels | Moderate — sometimes used intentionally to extend antibiotic levels |
| Allopurinol | Increased risk of skin rash when combined with amoxicillin | Low-Moderate — monitor for dermatologic reactions; relevant for dogs treated for leishmaniasis |
| Probiotics | Antibiotic kills probiotic bacteria if given simultaneously | Low — separate dosing by at least 2 hours |
| Oral bacterin vaccines | Antibiotics may interfere with live bacterial vaccines (e.g., oral Bordetella) | Low — delay vaccination until antibiotic course is complete |
Monitoring Requirements and Follow-Up
Typical Monitoring Plan During Clavamox Treatment
For standard 7–14 day courses (skin, dental, simple UTI):
- Owner observation of appetite, stool quality, and symptom improvement daily
- Phone check-in with vet clinic at day 3–5 if no improvement
- Recheck appointment at course completion if symptoms persist
For extended courses (4–6 weeks for deep infections, recurrent UTIs, pneumonia):
- Baseline CBC (complete blood count) and chemistry panel before starting — $80–$200 depending on clinic
- Mid-course recheck at 2–3 weeks to assess response
- Bacterial culture and sensitivity (C&S) before starting and 5–7 days after completing treatment — $60–$150 per culture
- For UTIs: follow-up urinalysis and ideally a urine culture 5–7 days post-treatment — $35–$80 for urinalysis
- Liver enzyme monitoring if treatment extends beyond 4 weeks or if dog has pre-existing liver concerns
According to the Merck Veterinary Manual, prolonged antibiotic use warrants periodic monitoring of hepatic (liver) and renal (kidney) function, especially in senior dogs or those with pre-existing organ dysfunction.
Cost and Generic Availability
One of Clavamox's advantages is its affordability, especially in generic form. Here are current typical costs at US veterinary pharmacies and online retailers in 2026:
| Product | Typical Price Range | Notes |
|---|---|---|
| Brand-name Clavamox chewable tablets (62.5 mg, 20 ct) | $35–$55 | Beef-flavored; Zoetis brand |
| Generic amoxicillin/clavulanate tablets (125 mg, 20 ct) | $12–$25 | Significant savings over brand |
| Generic amoxicillin/clavulanate tablets (250 mg, 20 ct) | $15–$30 | For medium-large dogs |
| Generic amoxicillin/clavulanate tablets (500 mg, 20 ct) | $18–$40 | For large/giant breeds |
| Oral suspension (reconstituted, 15 mL) | $20–$35 | Requires refrigeration; 10-day shelf life |
| Veterinary office visit + prescription | $60–$150 | Exam fee varies by region and clinic type |
Money-saving tip: Ask your veterinarian for a written prescription that you can fill at an accredited online pharmacy (e.g., Chewy Pharmacy, 1-800-PetMeds, or Costco's pet pharmacy). Generic versions contain the same active ingredients at the same concentrations and are FDA-approved. Savings of 40–60% compared to in-clinic dispensing are common.
Missed Dose and Overdose: What to Do
If You Miss a Dose
- Give the missed dose as soon as you remember — unless it's almost time for the next scheduled dose.
- If it's within 2–3 hours of the next dose, skip the missed dose and continue on schedule.
- Never double the dose to make up for a missed one. Doubling increases the risk of vomiting, diarrhea, and in rare cases, neurotoxic effects.
- If you've missed multiple doses (more than 24 hours without medication), contact your veterinarian. The infection may need reassessment, and a new prescription with adjusted duration may be needed.
If Your Dog Accidentally Overdoses
Amoxicillin-clavulanate has a relatively wide safety margin, but significant overdoses can cause:
- Severe vomiting and diarrhea
- Crystalluria (crystal formation in urine) leading to kidney damage — especially with massive overdoses in dehydrated dogs
- Neurological signs (seizures) at extremely high doses, particularly in dogs with pre-existing kidney disease
Immediate steps:
- Note the approximate amount ingested and the time
- Call your veterinarian or emergency veterinary clinic
- Contact ASPCA Animal Poison Control at (888) 426-4435 (24/7, consultation fee applies) for guidance
- Ensure your dog has access to plenty of fresh water to help prevent crystalluria
- Do not induce vomiting unless specifically instructed by a veterinary professional
Are There Alternatives to Clavamox?
If your dog cannot tolerate Clavamox, has a penicillin allergy, or the bacterial culture shows resistance, your veterinarian may consider these alternatives:
| Alternative Antibiotic | Drug Class | When Used Instead |
|---|---|---|
| Cephalexin (Simplicef) | First-generation cephalosporin | Skin infections; caution with penicillin allergy (5-10% cross-reactivity) |
| Doxycycline | Tetracycline | Tick-borne diseases, respiratory infections, penicillin-allergic dogs |
| Enrofloxacin (Baytril) | Fluoroquinolone | UTIs, deep infections; reserved for culture-confirmed resistance to first-line drugs per AVMA stewardship guidelines |
| Metronidazole (Flagyl) | Nitroimidazole | Anaerobic infections, GI infections; often combined with another antibiotic |
| Chloramphenicol | Phenicol | Multi-drug resistant infections; requires careful monitoring due to bone marrow suppression risk |
The choice of antibiotic should always be guided by bacterial culture and sensitivity testing whenever possible, especially for recurrent infections. The AVMA strongly advocates for antimicrobial stewardship — using the narrowest-spectrum antibiotic effective against the identified pathogen for the shortest effective duration.
Frequently Asked Questions About Clavamox for Dogs
Can I give my dog human amoxicillin-clavulanate (Augmentin)?
While the active ingredients are the same, human Augmentin formulations have different ratios of amoxicillin to clavulanate and different tablet strengths than veterinary Clavamox. Dosing a human product for a dog without veterinary guidance risks under- or overdosing. Additionally, some human liquid formulations contain xylitol as a sweetener, which is highly toxic to dogs. Always use a veterinary-prescribed product with your vet's specific dosing instructions.
My dog's symptoms improved after 3 days — can I stop the Clavamox early?
No. Clinical improvement does not mean the infection is fully eradicated. Stopping early leaves behind the most resistant bacteria, which can multiply and cause a recurrent infection that is harder to treat. This is one of the primary drivers of antimicrobial resistance. Always complete the full prescribed course unless your veterinarian explicitly tells you to stop.
Is Clavamox safe for pregnant or nursing dogs?
Amoxicillin is generally considered safe during pregnancy and lactation in dogs (FDA pregnancy Category B equivalent in human medicine). However, clavulanate has less reproductive safety data. Your veterinarian will weigh the benefits against any theoretical risks and may choose plain amoxicillin or another alternative for pregnant bitches when appropriate.
My dog has been on Clavamox for 5 days and still has diarrhea — is this normal?
Mild loose stools are one of the most common side effects. If the diarrhea is mild (soft but formed, 1–2 extra bowel movements per day), adding a probiotic separated by 2 hours from the antibiotic dose often helps. However, if diarrhea is watery, contains blood or mucus, is accompanied by vomiting or lethargy, or persists beyond 48 hours after starting probiotics, contact your veterinarian. In rare cases, antibiotic use can trigger Clostridium difficile overgrowth, which requires different treatment.
Can Clavamox be used for ear infections in dogs?
Clavamox is sometimes prescribed off-label for bacterial ear infections, particularly when the infection involves the middle ear or when topical treatments are not feasible. However, most uncomplicated otitis externa cases are treated with topical ear medications (such as Otomax, Osurnia, or Claro) rather than systemic oral antibiotics. Your vet will determine if oral Clavamox is appropriate based on cytology and culture of the ear discharge.
How should I store Clavamox?
Tablets should be stored at room temperature (68–77°F / 20–25°C) in their original container, away from moisture and direct sunlight. The reconstituted oral liquid suspension must be refrigerated (36–46°F / 2–8°C) and is only stable for 10 days after mixing. Discard any unused liquid after 10 days — do not save it for future use.
Does pet insurance cover Clavamox prescriptions?
Most comprehensive pet insurance plans (Trupanion, Healthy Paws, Nationwide, etc.) cover prescription medications when they're related to a covered condition. However, you typically pay the pharmacy cost upfront and submit for reimbursement. Some plans have prescription add-on riders that provide direct pharmacy payment. Check your specific policy — annual medication costs for antibiotics are usually well within standard coverage limits.
Disclaimer: This article is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian before starting, stopping, or adjusting any medication for your dog. Individual dogs may respond differently to treatment, and only a licensed veterinarian who has examined your pet can make appropriate prescribing decisions.
Marcus Aldridge
All our authors care for dogs every day — read more of their work on the authors page.
