Clavamox Dosage for Dogs: Safe Dosing Guide by Weight and Condition
Complete Clavamox dosage for dogs guide covering mg/kg dosing by condition, side effects, drug interactions, cost, and administration tips from veterinary experts.
If your dog has been prescribed Clavamox, you likely have questions about proper dosing, what to expect, and how to handle missed doses or side effects. Clavamox is one of the most commonly prescribed antibiotics in veterinary medicine — a broad-spectrum workhorse that treats everything from stubborn skin infections to bite wound abscesses. But getting the dose right matters enormously: too little won't clear the infection, while too much increases the risk of gastrointestinal upset and other adverse effects.
This guide breaks down exactly how veterinarians calculate Clavamox dosage for dogs, what conditions it treats, what side effects to watch for, and how to ensure your dog completes their course safely. All dosing information references the Merck Veterinary Manual and FDA-approved veterinary labeling.
What Is Clavamox and How Does It Work in Dogs?
Clavamox is a 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 sold under the brand name Clavamox in veterinary medicine. The human-equivalent formulation is Augmentin, though the tablet concentrations and ratios differ significantly between veterinary and human products.
Amoxicillin works by disrupting bacterial cell wall synthesis — specifically, it binds to penicillin-binding proteins (PBPs) that bacteria need to construct their protective cell walls. Without intact cell walls, bacteria burst and die. However, many bacteria have evolved a defense: they produce enzymes called beta-lactamases that destroy amoxicillin before it can work.
That's where clavulanate potassium comes in. It acts as a decoy — it binds to and neutralizes beta-lactamase enzymes, protecting the amoxicillin so it can do its job. This combination makes Clavamox effective against many bacteria that would otherwise resist amoxicillin alone, including beta-lactamase-producing strains of Staphylococcus, E. coli, and Pasteurella.
Clavamox is classified as a bactericidal antibiotic (it kills bacteria directly rather than just slowing their growth) and works best when blood levels remain consistently above the minimum inhibitory concentration (MIC) for the target organism. This is why consistent dosing intervals are so important.
FDA-Approved and Common Off-Label Uses
The FDA has approved Clavamox for specific veterinary indications, but veterinarians frequently prescribe it for additional conditions based on clinical evidence and susceptibility patterns.
FDA-Approved Uses in Dogs
- Skin and soft tissue infections: Wound infections, abscesses, cellulitis, and pyoderma caused by susceptible strains of Staphylococcus aureus, Staphylococcus intermedius, Streptococcus spp., and E. coli
- Periodontal (dental) infections: Gingivitis and periodontal disease caused by susceptible anaerobic and aerobic oral bacteria
Common Off-Label Uses
Under the Animal Medicinal Drug Use Clarification Act (AMDUCA), veterinarians may legally prescribe Clavamox for conditions beyond its labeled indications when clinical judgment supports it:
- Urinary tract infections (UTIs): Uncomplicated bacterial cystitis, particularly when E. coli or Proteus is suspected
- Respiratory tract infections: Bacterial pneumonia, tracheobronchitis, and kennel cough secondary bacterial infections
- Ear infections (otitis): As systemic support alongside topical therapy for middle ear infections
- Bite wound infections: Pasteurella multocida is a common bite wound pathogen and is typically susceptible to amoxicillin/clavulanate
- Anal gland abscesses: Post-drainage infection management
- Osteomyelitis: Bone infections, often as part of a broader treatment protocol
Clavamox Dosage for Dogs by Weight and Condition
The standard Clavamox dosage for dogs is calculated based on body weight and the severity and type of infection being treated. Clavamox tablets come in specific sizes: 62.5 mg, 125 mg, 250 mg, and 375 mg (total combined amoxicillin + clavulanate). The oral suspension (drops) contains 62.5 mg per mL.
The ratio of amoxicillin to clavulanate in veterinary Clavamox is 4:1 (amoxicillin:clavulanate). This differs from some human Augmentin formulations, which is one reason you should never substitute human tablets without explicit veterinary direction.
| Dog Weight | Standard Dose (Skin/Dental) | Higher Dose (Severe/Deep Infections) | Tablet Size Typically Used |
|---|---|---|---|
| 5 lb (2.3 kg) | 31.25 mg every 12 hours | 45 mg every 12 hours | 62.5 mg (half tablet) |
| 10 lb (4.5 kg) | 62.5 mg every 12 hours | 90 mg every 12 hours | 62.5 mg (1 tablet) |
| 20 lb (9.1 kg) | 125 mg every 12 hours | 180 mg every 12 hours | 125 mg (1 tablet) |
| 35 lb (15.9 kg) | 218.75 mg every 12 hours | 315 mg every 12 hours | 250 mg (1 tablet) |
| 50 lb (22.7 kg) | 312.5 mg every 12 hours | 450 mg every 12 hours | 375 mg (1 tablet) |
| 75 lb (34.1 kg) | 468.75 mg every 12 hours | 675 mg every 12 hours | 375 mg + 125 mg |
| 100 lb (45.5 kg) | 625 mg every 12 hours | 900 mg every 12 hours | 375 mg + 250 mg |
Dosing formula: The standard dose is 6.25 mg per pound (13.75 mg/kg) of combined amoxicillin/clavulanate, given orally every 12 hours. For severe or deep-seated infections, your veterinarian may increase this to 9 mg per pound (20 mg/kg) every 12 hours.
Example calculation: A 30 lb (13.6 kg) dog with a standard skin infection would receive 30 × 6.25 = 187.5 mg every 12 hours. Your vet would likely prescribe the 125 mg tablet plus half of a 125 mg tablet (187.5 mg total), or may round to the 250 mg tablet depending on clinical judgment and tablet availability.
How to Administer Clavamox to Your Dog
Clavamox is available in two forms for dogs: chewable tablets and oral suspension (liquid drops). Proper administration affects both how well the drug is absorbed and how well your dog tolerates it.
Chewable Tablets
- With or without food: Clavamox can be given with or without food, but giving it with a small meal significantly reduces the chance of vomiting and diarrhea — the most common side effects
- Storage: Chewable tablets should be stored at room temperature (68–77°F / 20–25°C) in their original packaging. They are moisture-sensitive, so don't remove them from the foil blister pack until ready to use
- Administration: Most dogs accept the chewable tablets readily due to their beef-pork flavoring. If your dog spits it out, try hiding it in a small amount of canned food, peanut butter (xylitol-free), or a pill pocket treat
Oral Suspension (Liquid)
- Reconstitution: The powder must be mixed with water by your pharmacy or veterinary clinic. Once reconstituted, it must be refrigerated (36–46°F / 2–8°C)
- Shelf life after mixing: Discard any unused suspension after 10 days — it loses potency and can develop bacterial contamination
- Shake well: Always shake the bottle vigorously for 5–10 seconds before each dose to ensure even distribution of the medication
- Dosing syringe: Use the provided oral syringe for accuracy. Household teaspoons are unreliable — a "teaspoon" can vary from 3.5 mL to 7 mL depending on the spoon
Treatment Duration
The typical course of Clavamox runs 7 to 14 days for most skin and soft tissue infections. Dental infections may require 7–10 days. Urinary tract infections often need 7–14 days, while deep-seated infections like osteomyelitis may require 4–8 weeks of continuous therapy.
The most common mistake dog owners make is stopping the antibiotic early because their dog "looks better." Stopping prematurely allows partially resistant bacteria to survive and multiply, potentially creating an infection that is harder to treat the second time around. Always complete the full prescribed course unless your veterinarian tells you otherwise.
Side Effects: What to Expect and When to Worry
Like all antibiotics, Clavamox can cause side effects. The clavulanate component, in particular, tends to irritate the gastrointestinal tract. Most side effects are mild and manageable, but some require immediate veterinary attention.
| Side Effect | Estimated Frequency | Severity | What to Do |
|---|---|---|---|
| Diarrhea / loose stools | 15–25% of dogs | Mild | Give with food; add probiotic 2 hours after dose; call vet if persists >48 hours |
| Vomiting | 10–15% of dogs | Mild to moderate | Give with food; if vomiting occurs within 30 min of dose, call vet about redosing |
| Decreased appetite | 5–10% of dogs | Mild | Offer small, frequent meals; monitor for >24 hours of not eating |
| Drooling / nausea | 3–5% of dogs | Mild | Usually passes in 30–60 minutes; give with food next time |
| Allergic reaction (hives, facial swelling) | <1% of dogs | SERIOUS | Stop medication and contact vet immediately |
| Anaphylaxis (collapse, difficulty breathing) | Very rare (<0.1%) | EMERGENCY | Rush to nearest emergency vet clinic immediately |
| Severe bloody diarrhea | Rare | SERIOUS | Stop medication and call vet — may indicate antibiotic-associated colitis |
- Facial swelling, hives, or itchy welts appearing within hours of dosing
- Difficulty breathing, wheezing, or collapse
- Vomiting that persists for more than 24 hours or prevents your dog from keeping water down
- Bloody or black, tarry diarrhea
- Your dog becomes severely lethargic or unresponsive
- Yellowing of the gums or whites of the eyes (icterus) — may indicate liver involvement
- No improvement in the original infection after 48–72 hours of treatment
Managing Mild GI Side Effects at Home
If your dog develops mild diarrhea or vomiting on Clavamox, these strategies can help while you continue the prescribed course:
- Always give with food: A full stomach significantly reduces clavulanate-related GI irritation
- Add a canine probiotic: Products like Purina FortiFlora or Proviable-DC can help maintain gut flora. Give the probiotic at least 2 hours after the antibiotic dose so the antibiotic doesn't immediately kill the beneficial bacteria
- Bland diet support: If appetite drops, offer boiled chicken breast and white rice in small portions
- Hydration: Ensure fresh water is always available; diarrhea increases fluid loss
Contraindications and Drug Interactions
Clavamox is not appropriate for every dog. Certain health conditions and concurrent medications can make it unsafe or less effective.
Contraindications — Dogs Who Should NOT Receive Clavamox
- Known penicillin or cephalosporin allergy: Dogs with a documented allergic reaction to any penicillin-family antibiotic (amoxicillin, ampicillin, penicillin G) or cephalosporins (cephalexin, cefpodoxime) should not receive Clavamox. Cross-reactivity between penicillins and cephalosporins occurs in approximately 1–3% of allergic individuals
- Severe kidney disease: Amoxicillin is primarily excreted by the kidneys. Dogs with advanced renal failure (IRIS Stage 3–4) may need dose reduction or an alternative antibiotic to prevent toxic accumulation
- History of antibiotic-associated liver injury: While rare, amoxicillin/clavulanate has been associated with idiosyncratic hepatotoxicity. Dogs with a prior episode should use an alternative
- Very young puppies with immature renal function: Puppies under 4 weeks of age may not metabolize the drug efficiently. Your veterinarian will weigh risks and benefits carefully
Drug Interactions
| Concurrent Drug | Interaction Type | Clinical Significance | Management |
|---|---|---|---|
| Bacteriostatic antibiotics (tetracycline, chloramphenicol, erythromycin) | Antagonistic | Moderate — bacteriostatic drugs slow bacterial growth, which reduces the effectiveness of bactericidal penicillins that target actively dividing cells | Avoid concurrent use unless directed by your veterinarian |
| Probenecid | Pharmacokinetic | Moderate — probenecid blocks renal tubular secretion of amoxicillin, increasing blood levels and prolonging half-life | May be used intentionally to boost levels; vet will adjust dose |
| Methotrexate | Toxicity increase | High — penicillins reduce renal clearance of methotrexate, increasing risk of methotrexate toxicity | Avoid combination; choose alternative antibiotic |
| Mycophenolate | Reduced efficacy | Moderate — amoxicillin/clavulanate may reduce enterohepatic recirculation of mycophenolate, lowering immunosuppressive levels | Monitor mycophenolate levels; vet may adjust dose |
| Oral bacterin vaccines (e.g., leptospirosis oral vaccine) | Reduced vaccine efficacy | Moderate — antibiotics may kill the live bacterial components of oral vaccines | Separate vaccination and antibiotic course by at least 7 days |
Always provide your veterinarian with a complete list of every medication, supplement, and over-the-counter product your dog is taking before starting Clavamox. This includes flea/tick preventives, joint supplements, fish oils, and any herbal remedies.
Monitoring, Follow-Up, and Cost Information
What Your Veterinarian Will Monitor
- Short courses (7–14 days): Typically no blood work required for otherwise healthy dogs. Your vet will schedule a recheck appointment within 1–2 weeks to assess infection resolution
- Extended courses (>3 weeks): Baseline blood chemistry panel (kidney values: BUN, creatinine, SDMA; liver values: ALT, ALP, bilirubin) before starting, then recheck every 2–4 weeks
- Dogs with pre-existing kidney or liver disease: Blood work before starting, at 2 weeks, then monthly. Dose adjustments may be needed based on results
- Culture and sensitivity testing: For recurrent or non-responsive infections, your vet may collect a bacterial culture before or during treatment to confirm the organism is susceptible to Clavamox. Culture results typically take 48–72 hours
Cost and Availability
Clavamox is available as a brand-name product from Zoetis and as generic amoxicillin/clavulanate potassium from several pharmaceutical manufacturers. Generic versions are FDA-approved and therapeutically equivalent.
| Form | Brand (Clavamox) | Generic | Notes |
|---|---|---|---|
| 62.5 mg tablets (per tablet) | $1.50–$2.50 | $0.75–$1.50 | For small dogs <15 lb |
| 125 mg tablets (per tablet) | $2.00–$3.25 | $1.00–$2.00 | For dogs 15–30 lb |
| 250 mg tablets (per tablet) | $2.75–$4.00 | $1.50–$2.50 | For dogs 30–55 lb |
| 375 mg tablets (per tablet) | $3.50–$5.00 | $2.00–$3.50 | For dogs 55+ lb |
| Oral suspension 15 mL bottle | $18–$30 | $12–$22 | Best for puppies and small dogs; discard after 10 days |
Typical total course cost: For a 30 lb dog on a 10-day course of 125 mg tablets (20 tablets total), expect to pay $20–$65 depending on brand vs. generic and whether you purchase through your veterinary clinic or an accredited online pharmacy like Chewy Pharmacy or 1-800-PetMeds (both require a valid prescription).
Cost-saving tip: Ask your veterinarian if a generic equivalent is appropriate. Generic amoxicillin/clavulanate typically costs 40–50% less than brand-name Clavamox with the same clinical effectiveness. Some veterinary clinics also offer price-matching with accredited online pharmacies.
Missed Doses and Overdose: What to Do
If You Miss a Dose
- If it's been less than 6 hours since the missed dose: Give the missed dose as soon as you remember, then adjust the next dose to maintain the 12-hour interval. For example, if the 8 AM dose was missed and you remember at noon, give it at noon and shift the evening dose to midnight (or as close as practical)
- If it's almost time for the next dose: Skip the missed dose entirely and give the next scheduled dose at the regular time. Do NOT double the dose to make up for the missed one
- If you miss more than 2 consecutive doses: Call your veterinarian. Missing multiple doses can allow the infection to rebound and may require a different treatment approach or extended course
If Your Dog Receives Too Much (Overdose)
Amoxicillin/clavulanate has a relatively wide safety margin, and a single extra dose is unlikely to cause life-threatening toxicity. However, significant overdoses can cause severe gastrointestinal distress, crystal formation in the urine (crystalluria), and in extreme cases, seizures or kidney damage.
If your dog ingests significantly more than the prescribed amount:
- Do not induce vomiting unless instructed by a veterinarian
- Call your veterinarian or the nearest emergency clinic immediately
- Contact ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies) or the Pet Poison Helpline: (855) 764-7661 for guidance
- Bring the medication packaging with you to the clinic so the veterinary team can calculate the exact ingested amount
Overdose symptoms to watch for: profuse vomiting, severe diarrhea (possibly bloody), excessive drooling, tremors, seizures, or inability to urinate. Dogs with pre-existing kidney disease are at higher risk for complications from overdose.
Alternatives to Clavamox for Dogs
Clavamox isn't the only option for bacterial infections, and your veterinarian may choose an alternative based on culture results, your dog's medical history, or drug availability.
| Alternative Antibiotic | Drug Class | When It's Preferred Over Clavamox | Key Limitations |
|---|---|---|---|
| Cephalexin (Simplicef) | First-gen cephalosporin | Skin infections with confirmed methicillin-susceptible Staphylococcus; dogs with mild penicillin sensitivity (with vet approval) | Less effective against anaerobic bacteria; cross-reactivity risk in penicillin-allergic dogs |
| Doxycycline | Tetracycline | Tick-borne diseases (Lyme, Ehrlichia), respiratory infections, leptospirosis | Not ideal for skin/soft tissue; can cause esophageal strictures in cats (less concern in dogs) |
| Enrofloxacin (Baytril) | Fluoroquinolone | Gram-negative infections, UTIs resistant to first-line drugs, prostate infections | Avoid in growing puppies (cartilage damage risk); reserved for resistant infections per AVMA antimicrobial stewardship guidelines |
| Metronidazole (Flagyl) | Nitroimidazole | Anaerobic infections, giardia, certain GI infections | Narrow spectrum; neurotoxicity risk at high doses; very bitter taste |
Your veterinarian's choice of antibiotic should ideally be guided by bacterial culture and sensitivity testing, especially for recurrent or non-responsive infections. The AVMA's antimicrobial stewardship guidelines emphasize using the narrowest-spectrum antibiotic effective for the specific infection to reduce resistance development.
Frequently Asked Questions About Clavamox
Can I give my dog human Augmentin instead of Clavamox?
No. While Augmentin contains the same active ingredients (amoxicillin and clavulanate), the tablet strengths, ratios, and inactive ingredients differ between the human and veterinary formulations. Human Augmentin tablets often contain higher clavulanate ratios that increase GI side effects in dogs, and some formulations contain xylitol or other inactive ingredients that can be harmful. Only use veterinary-prescribed Clavamox or its approved generic equivalent.
How long does it take for Clavamox to start working?
Most dogs begin showing improvement within 24–48 hours of starting Clavamox. You may notice reduced redness, swelling, or discharge from wound sites, improved energy levels, and better appetite. However, visible improvement does not mean the infection is cured — continue the full course as prescribed. If there is no improvement at all after 72 hours, contact your veterinarian, as the bacteria may be resistant and a different antibiotic may be needed.
Can I give my dog a probiotic while on Clavamox?
Yes, and it's generally recommended. Probiotics can help reduce antibiotic-associated diarrhea by replenishing beneficial gut bacteria. The key is timing: give the probiotic at least 2 hours after the Clavamox dose. If given simultaneously, the antibiotic will kill the probiotic bacteria before they can colonize the gut. Recommended products include Purina FortiFlora (Enterococcus faecium SF68) or Nutramax Proviable-DC (multi-strain).
Is Clavamox safe for pregnant or nursing dogs?
Amoxicillin is generally considered safe during pregnancy (Category B in human medicine, and widely used in veterinary reproduction). However, clavulanate has less reproductive safety data. Your veterinarian will evaluate the risk-benefit ratio and may prescribe amoxicillin alone rather than the combination if the infection is susceptible. Always inform your vet if your dog is pregnant, may be pregnant, or is nursing.
My dog is allergic to penicillin — can they still take Clavamox?
No. Clavamox contains amoxicillin, which is a penicillin-family antibiotic. If your dog has a documented penicillin allergy (hives, facial swelling, anaphylaxis after previous penicillin exposure), Clavamox is contraindicated. Your veterinarian will select an antibiotic from a different drug class, such as a cephalosporin (with caution due to cross-reactivity risk), a macrolide, or a fluoroquinolone, depending on the infection type and culture results.
Can Clavamox treat ear infections in dogs?
Clavamox may be used as a systemic antibiotic for middle ear infections (otitis media) or severe outer ear infections with deep tissue involvement. However, most uncomplicated outer ear infections (otitis externa) are treated with topical ear drops rather than oral antibiotics. Your veterinarian will examine your dog's ear canals with an otoscope and may take a cytology sample to determine whether systemic antibiotics are needed.
What should I do if my dog vomits right after taking Clavamox?
If your dog vomits within 15–30 minutes of taking the dose and you can see the tablet in the vomit, wait 30 minutes and try redosing with a small amount of food. If vomiting occurs more than 30 minutes after administration, a significant portion of the drug has likely been absorbed — do not redose, but note the incident and mention it at your next vet communication. If vomiting persists with every dose, contact your veterinarian about switching to a different antibiotic or adding an anti-nausea medication like maropitant (Cerenia).
This article is intended for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian regarding your dog's specific medical needs, medication dosages, and treatment plans. If your dog is experiencing a medical emergency, contact your nearest veterinary clinic or emergency animal hospital immediately.
Jonas Cole
All our authors care for dogs every day — read more of their work on the authors page.
