The clinical efficacy of danofloxacin 2.5% (Advocin (R)) in the treatment of Escherichia coli infections and in vitro activity against enteric pathogens in pigs.

Studies were conducted in vitro and in vivo to investigate the efficacy of danofloxacin against Escherichia coli infections in pigs. Minimum inhibitor y concentrations (MIC's) for danofloxacin were determined for isolates of E . coli collected from clinical cases of enteric disease across seven Europe an countries. In vivo assessment was undertaken in both a colostrum-restric ted neonatal piglet model with induced E. coli infection where 39 and 41 pi glets were treated respectively with saline or danofloxacin 2.5% at 1.25 mg /kg, and in a series of field studies conducted in commercial units in four European countries. Piglets with signs of enteritis caused by E. coli were treated once daily (SID) on days 0, 1 and 2, with either danofloxacin (n=2 63), or an approved reference product (trimethoprim/sulphadoxine n=43, or a moxycillin n=90). Efficacy was assessed over a seven-day period on the basi s of clinical scores and average daily weight gain. The range of MIC values for danofloxacin against E. coli isolates from cases of enteric disease (n =112) was less than or equal to0.015 to >2.0 mug/mL (MIC90 = 0.25 mug/mL). In the in vivo studies, there were no suspected adverse drug experiences. I n colostrum-restricted neonatal piglets, mortality due to enteritis was 40% for the saline-treated controls, compared with 0% for piglets receiving da nofloxacin (P<0.001). In the field studies, there were no significant diffe rences (P>0.05) between treatments. Reductions in the severity of clinical signs of diarrhoea on days 4 and 7 compared with day 0 were highly signific ant (P<0.0001) for both treatments, as were reductions in signs of depressi on for piglets treated with danofloxacin. For piglets treated with referenc e products, signs of depression were significantly reduced from day 0 on da y 7 (P<0.05) but not on day 4. Danofloxacin was shown to be safe and highly effective in the treatment of porcine enteric disease caused by E. coli.