Amoxicillin/Clavulanic Acid (Clavamox®)
Amoxicillin/potassium clavulanate tablets and oral suspension products are FDA-approved for use in dogs and cats for the treatment of urinary tract, skin and soft tissue infections caused by susceptible organisms. It is also indicated for canine periodontal disease due to susceptible strains of bacteria. According to one reference (Trepanier 2009), amoxicillin + clavulanate is a reasonable first choice for empiric treatment (before culture and susceptibility results are back) of bacterial cystitis in female dogs, and hepatobiliary infections (with a fluoroquinolone) in dogs or cats.
Adverse effects with the penicillins are usually not serious and have a relatively low frequency of occurrence. Hypersensitivity reactions unrelated to dose can occur with these agents and can manifest as rashes (including serious cutaneous reactions), fever, eosinophilia, neutropenia, agranulocytosis, thrombocytopenia, leukopenia, anemia, lymphadenopathy, or full-blown anaphylaxis. When given orally, penicillins may cause GI effects (anorexia, vomiting, diarrhea). Because the penicillins may alter gut flora, antibiotic-associated diarrhea can occur and allow the proliferation of resistant bacteria in the colon (superinfections).
Neurotoxicity (e.g., ataxia in dogs) has been associated with very high doses or very prolonged use. Although the penicillins are not considered hepatotoxic, elevated liver enzymes have been reported. Other effects reported in dogs include tachypnea, dyspnea, edema and tachycardia.