Otitis externa in the dog -- a clinical and microbiological study.

The effect on canine otitis externa of a topical preparation composed of Fucidin, Framycetin, Nystatin, and Prednisolone was evaluated in a clinical trial comprising 235 dog ears. Cases caused by parasites or foreign bodies and cases requiring systemic therapy were excluded. Swabs from these and an additional 434 affected ears were examined bacteriologically and the sensitivity to antibiotics of the bacteria isolated determined. The infection most frequently diagnosed was staphylococci plus yeasts (29 % of total material) followed by pure yeast-infections (19 %) and pure staphylococcus infections (16 %). Pseudomonas aeruginosa and/or Proteus mirabilis were found in 7 % of the ears, while no organisms could be isolated from 22 %. Sensitivity tests showed a satisfactory in vitro effect of Neomycin (Framycetin) on most of the bacteria commonly isolated, and a very good effect of Fucidin on the staphylococci. Approximately 91 % of the ears treated were clinically cured or improved very considerably; the relation between clinical response and type of infection is shown diagrammatically in Fig. 1. It was confirmed that infections with Ps. aeruginosa represent a special problem; the results of post-treatment sensitivity tests seem to suggest, however, that a longer or more intense course of treatment than the one used in the trial (two weeks) would provide the answer to this.