SUSCEPTIBILITY OF BACTERIAL ISOLATES FROM CHRONIC CANINE OTITIS-EXTERNA TO 20 ANTIBIOTICS

In this paper we present the results of studies on the susceptibility to antibiotics of bacteria isolated from chronic canine otitis externa . We tested 46 bacterial strains (S. aureus, coagulase-negative staphy lococci, Corynebacterium spp., and gram-negative bacilli) with 20 diff erent antibiotics. We observed increased resistance to antibiotics of bacteria isolated from canine otitis externa as compared to the resist ance reported earlier. This may be due to the indiscriminate use of so me antibiotics in the last years and indicates the importance of sensi tivity testing for the effective treatment of chronic otitis externa, especially that caused by gram-negative bacilli. The clinician may ini tiate empiric treatment with antibiotics before obtaining the sensitiv ity test results; the best results may be expected from a topical appl ication of Bacitracin or Chloramphenicol, and from a systemic therapy with Cephalosporines. Therapeutical scheme for treating various bacter ial groups are presented in the paper.