Susceptibility of Pseudomonas isolates from the ears and skin of dogs to enrofloxacin, marbofloxacin, and ciprofloxacin.

The purpose of this study was to compare susceptibilities of ear and skin Pseudomonas spp. isolates to enrofloxacin, marbofloxacin, and ciprofloxacin. Specimens were obtained from dogs examined in a veterinary dermatology referral hospital. Susceptibilities of ear isolates to enrofloxacin, marbofloxacin, and ciprofloxacin were 46.9%, 66.7%, and 75.0%, respectively. Susceptibilities of skin isolates to the same drugs were 76.2%, 81.0%, and 80.0%, respectively. Ear isolates were significantly less susceptible to enrofloxacin than to ciprofloxacin (P=0.021), and ear isolates were significantly less susceptible to enrofloxacin than were skin isolates (P=0.034). When fluoroquinolone resistance was present, ear isolates were significantly less susceptible to enrofloxacin than to ciprofloxacin (P<0.001) and marbofloxacin (P=0.014).