Initial antimicrobial treatment of foals with sepsis: Do our choices make a difference?

The study objectives were to provide cumulative antimicrobial susceptibility data at the patient level and to evaluate the effect of initial antimicrobial treatment on survival in foals with sepsis. Foals below 30days of age with a diagnosis of sepsis, confirmed by isolation of bacteria from normally sterile sites on the day of hospital admission, were included. Susceptibility testing was performed using the broth microdilution procedure. In total, 213 foals and 306 bacterial isolates were included. The likelihood of survival for foals from which all bacteria were susceptible to the initial antimicrobial treatment was 65.4% (n=106/162; 95% confidence interval (CI) 57.6% to 72.7%) versus 41.7% (n=10/24; 95% CI 22.1% to 63.4%) if one or more isolates were resistant (relative risk 1.57, 95% CI 0.96 to 3.06). Based on this study, amikacin combined with ampicillin remains an appropriate antimicrobial drug combination for initial treatment of foals with sepsis.