Emergence of drug-resistant bacteria in companion animals has led to increased importance of culture and susceptibility testing for selection of antimicrobial drugs, as well as understanding of minimum inhibitory concentration (MIC) and clinical breakpoints as related to susceptibility versus resistance. Nevertheless, culture should only be recommended in cases with reasonable likelihood of infection and in which test results can influence antimicrobial selection. Culturing bacteria that are not clinically relevant or are more appropriately treated with topical rather than systemic antimicrobials can misuse pet owner resources and veterinary team time and efforts and may lead to inappropriate treatment.
In cases in which culture and susceptibility testing are indicated and believed to result in isolation of clinically meaningful bacteria, antimicrobials not likely to attain adequate concentrations at the site of infection or that are contraindicated because of patient factors should be deprioritized first.