Selected Antimicrobial Information – Companion Animal

Amoxicillin-Clavulanic Acid [Companion]

Restriction Status



Species Usage Dose
Cats Label dose 62.5mg/cat PO q12h; duration of treatment not exceeding 30d
For uncomplicated UTI
62.5mg/cat PO q12h for 10-30d
For skin (pyoderma) or soft tissue infections 62.5mg/cat PO q12h for 5-7d or 11-22mg/kg PO q12h for 7-10d, or until infection has cleared (extra-label use)
For sepsis  10-20mg/kg PO q8h for 7-10d (extra-label use)
Dogs Label dose 13.75mg/kg PO q12h; duration of treatment not exceeding 30d
For uncomplicated UTI 12.5mg/kg PO q12h for 5-7d (extra-label use)
For skin (superficial pyoderma) and soft tissue infections 12.5-25mg/kg PO q12h to resolution of clinical signs or one week past resolution (extra-label use)
For deep pyoderma
12.5-25mg/kg q12h for 14d or longer
For systemic infections, including bacteremia or infectious endocarditis 12.5-25mg/kg PO q8h (extra-label use)

Brand Name(s)

Clavamox®, Augmentin®


Amoxicillin-clavulanic acid is a bactericidal, time-dependent β-lactam antibiotic with improved activity against Gram-negative organisms when compared to penicillin. The addition of clavulanic-acid improves activity against β-lactamase-producing bacteria. Activity against Gram-positive organisms is comparable to amoxicillin and ampicillin. Amoxicillin-clavulanic acid distributes widely through the plasma, and can cross the blood-brain barrier when meninges are inflamed although it is uncertain if therapeutic concentrations are achieved. It does not penetrate abscesses or sites of tissue necrosis well. Excretion is primarily as unchanged drug in urine.

Except for uncomplicated (lower) urinary tract infections, amoxicillin-clavulanic acid should not be used to treat infections caused by Enterobacterales (e.g., E. coli, Klebsiella spp., Proteus spp., Enterobacter spp.) due to the inability of this drug to reach an effective inhibitory serum concentration for the required period when recommended dose regimen are used.

Acceptable Uses

  • Treatment of skin and soft tissue infections, particularly those associated with β-lactamase-producing Staphylococcus pseudintermedius and other Staphylococcus spp (aureus, schleiferi, coagulans).
  • When used in combination with topical therapy, treatment of otitis media or interna (except for infections caused by Enterobacterales and methicillin-resistant Staphylococcus spp).
  • When used in combination with local therapy, treatment of gingivitis.
  • When used in combination with local therapy, for treatment of anal sacculitis.
  • Treatment of respiratory tract infections, including bacterial feline upper respiratory tract infections with a confirmed or highly suspected bacterial component, and infections in dogs associated with Bordetella bronchiseptica.
  • Less preferred empirical treatment of uncomplicated urinary tract infections, particularly those caused by susceptible E. coli or Proteus spp.
  • As an oral alternative to ampicillin-sulbactam.

Unacceptable Uses

  • Soft-tissue infections (e.g., wounds, otitis, pneumonia, among others) caused by Enterobacterales.

Formulations Available within the OSU Pharmacy

  • Clavamox 62.5mg/ml oral suspension
  • Clavamox 62.5mg tablet
  • Clavamox 125mg tablet
  • Clavamox 250mg tablet
  • Clavamox 375mg tablet


  • Clavulanic acid has a shorter half-life than amoxicillin, leading some pharmacologists to advocate q8h dosing to maintain a ratio of amoxicillin to clavulanic acid with optimal bactericidal activity.
  • Amoxicillin is preferred over amoxicillin-clavulanic acid for treatment of uncomplicated (lower) UTI. Clavulanic acid adds little to overall activity against Gram-negative aerobes such as E. coli, which are the most likely differential diagnosis. Amoxicillin has a narrower spectrum of activity and is the more responsible stewardship choice.


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OSU VMC Antimicrobial Use Guidelines Copyright © 2018 by The Ohio State University College of Veterinary Medicine is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.