Clavamox for Dogs: Side Effects, Dosage, and Safety Guide

What Is Clavamox and Why Vets Prescribe It

Clavamox is a broad-spectrum antibiotic combining amoxicillin (a penicillin-class antibiotic) with clavulanic acid (a beta-lactamase inhibitor). The clavulanic acid component prevents certain bacteria from destroying the amoxicillin, making this combination effective against resistant strains that plain amoxicillin cannot handle.

FDA-Approved Veterinary Uses

• Skin infections: Wounds, abscesses, cellulitis, and dermatitis caused by susceptible bacteria
• Urinary tract infections (UTIs): Uncomplicated bacterial cystitis
• Periodontal infections: Dental infections and post-dental procedure prophylaxis

Common Off-Label Uses

Veterinarians frequently prescribe Clavamox for respiratory infections, bone infections (osteomyelitis), and certain gastrointestinal infections when culture results indicate susceptibility. Your vet may also use it empirically while awaiting culture results for suspected bacterial infections.

Typical Clavamox Dosage by Condition and Weight

The standard dosing range for Clavamox in dogs is 6.25 mg per pound of body weight (13.75 mg/kg) given twice daily. However, your veterinarian will determine the exact dose based on infection type, severity, and your dog's individual health status.

Condition	Dose (mg/lb)	Frequency	Duration
Skin infections	6.25 mg/lb	Twice daily	7-14 days
Urinary tract infections	6.25 mg/lb	Twice daily	7-14 days
Dental infections	6.25 mg/lb	Twice daily	5-10 days
Respiratory infections	6.25-12.5 mg/lb	Twice daily	10-21 days

Example Dosage Calculations

20 lb dog with skin infection: 20 lb × 6.25 mg/lb = 125 mg per dose, given twice daily (250 mg total daily)

50 lb dog with UTI: 50 lb × 6.25 mg/lb = 312.5 mg per dose, given twice daily (625 mg total daily)

Clavamox is available in several tablet sizes: 62.5 mg, 125 mg, 250 mg, and 375 mg. Your vet will select the most appropriate tablet size to match your dog's calculated dose.

Clavamox Side Effects: What to Watch For

Most dogs tolerate Clavamox well, but like all antibiotics, it can cause side effects. Understanding which reactions are common and which require immediate veterinary attention helps you monitor your dog effectively during treatment.

Side Effect	Frequency	Severity	Action Required
Vomiting	5-10% of dogs	Mild	Give with food; contact vet if persistent
Diarrhea	5-10% of dogs	Mild to moderate	Monitor; probiotics may help
Decreased appetite	3-5% of dogs	Mild	Offer with meals; usually resolves
Allergic reaction (hives, facial swelling)	<1% of dogs	Serious	Emergency vet visit required
Severe watery/bloody diarrhea	Rare	Serious	Contact vet immediately
Difficulty breathing	Very rare	Life-threatening	Emergency vet visit required

Managing Common Side Effects

Administering Clavamox with food significantly reduces gastrointestinal upset. If your dog vomits within 30 minutes of dosing, contact your veterinarian for guidance—they may recommend redosing. For mild diarrhea, a canine-specific probiotic (such as Purina FortiFlora or Proviable) can help maintain healthy gut bacteria during antibiotic treatment.

Contraindications: Dogs Who Should Not Take Clavamox

Clavamox is contraindicated in dogs with known allergies to penicillin or cephalosporin antibiotics. Cross-reactivity between penicillin and cephalosporin classes occurs in approximately 1-3% of cases, so inform your veterinarian if your dog has reacted to any beta-lactam antibiotic previously.

Use with Caution

Your veterinarian will weigh risks and benefits carefully in these situations:

• Kidney disease: Amoxicillin is primarily excreted through kidneys; dose adjustment may be necessary
• Liver disease: Clavulanic acid has been rarely associated with liver enzyme elevation
• Pregnancy: While generally considered safe, your vet will assess necessity versus risk
• Very young puppies: Immature kidney function may require dose modification

Drug Interactions

Clavamox can interact with other medications your dog may be taking. Always provide your veterinarian with a complete list of current medications, supplements, and over-the-counter products.

Medication	Interaction Type	Clinical Significance
Bacteriostatic antibiotics (tetracyclines, chloramphenicol)	Reduced efficacy	Avoid concurrent use when possible
Probenecid	Increased amoxicillin levels	May require dose adjustment
Methotrexate	Increased methotrexate toxicity	Avoid combination
Oral contraceptives (in breeding dogs)	Reduced contraceptive efficacy	Use alternative contraception
Allopurinol	Increased rash risk	Monitor for skin reactions

Administration Instructions and Treatment Duration

Clavamox tablets can be given with or without food, but administering with meals reduces gastrointestinal side effects. The liquid suspension must be refrigerated after reconstitution and discarded after 10 days.

Proper Administration Technique

1. Give medication at consistent 12-hour intervals (e.g., 8 AM and 8 PM) to maintain therapeutic blood levels
2. For tablets, place at the back of the tongue and close the mouth, gently stroking the throat to encourage swallowing
3. For liquid suspension, use the provided syringe and administer slowly into the cheek pouch
4. Shake liquid suspension well before each use
5. Complete the entire prescribed course, even if your dog appears recovered

Why Completing the Full Course Matters

Stopping antibiotics prematurely allows surviving bacteria to develop resistance. These resistant bacteria can cause recurrent infections that are harder to treat and may spread to other animals or humans. The American Veterinary Medical Association emphasizes that antibiotic stewardship protects both individual animals and public health.

Monitoring and Follow-Up

Timepoint	Monitoring Activity	Purpose
Day 3-5	Phone check-in or recheck exam	Assess response to treatment
End of treatment	Recheck examination	Confirm infection resolution
2 weeks post-treatment (UTIs)	Urinalysis and culture	Verify bacterial clearance
Long-term use (>14 days)	Blood chemistry panel	Monitor kidney and liver function

For recurrent UTIs or skin infections, your veterinarian may recommend bacterial culture and sensitivity testing before starting Clavamox. This test identifies the specific bacteria present and determines which antibiotics will be most effective, preventing unnecessary broad-spectrum antibiotic use.

Missed Doses and Overdose

If You Miss a Dose

Give the missed dose as soon as you remember, unless it's nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular schedule. Never double-dose to make up for a missed one, as this increases the risk of side effects without improving efficacy.

Overdose Symptoms and Response

Clavamox has a wide safety margin, but significant overdose can cause severe vomiting, diarrhea, and dehydration. If your dog ingests more than twice the prescribed dose, contact your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 (24/7, consultation fee applies).

Overdose treatment typically involves supportive care: IV fluids for dehydration, anti-nausea medication, and monitoring of kidney function through blood work.

Cost and Availability

Clavamox is available as a brand-name product (Zoetis) and as generic amoxicillin-clavulanate. Generic versions offer significant cost savings while maintaining equivalent efficacy.

Price Ranges (2026)

• Brand-name Clavamox tablets (62.5 mg, 100 count): $85-$120
• Generic amoxicillin-clavulanate tablets (62.5 mg, 100 count): $35-$55
• Brand-name Clavamox oral suspension (50 mg/mL, 15 mL): $45-$65
• Generic oral suspension (50 mg/mL, 15 mL): $25-$40

Many veterinary pharmacies and online retailers (Chewy, 1-800-PetMeds, VetRxDirect) offer competitive pricing with a valid prescription. Your veterinarian can provide a written prescription allowing you to shop for the best price.

Alternatives to Clavamox

Your veterinarian may recommend alternatives based on culture results, your dog's medical history, or treatment response:

• Cephalexin: First-generation cephalosporin effective for many skin infections; similar dosing schedule
• Enrofloxacin (Baytril): Fluoroquinolone antibiotic for resistant infections; once-daily dosing; not for growing puppies
• Doxycycline: Tetracycline-class antibiotic; effective for respiratory and tick-borne diseases
• Trimethoprim-sulfamethoxazole (TMS): Broad-spectrum option for UTIs and respiratory infections

The choice between Clavamox and alternatives depends on the specific bacteria involved, infection location, your dog's health status, and previous antibiotic exposure. Culture and sensitivity testing guides this decision for recurrent or severe infections.

Always consult your veterinarian before starting, stopping, or modifying any medication regimen. This guide provides general information and does not replace professional veterinary advice.