Incidence of otitis externa in dogs and cats in Japan.

The incidence of otitis externa in dogs and cats admitted to the animal hospital of the University of Osaka Prefecture was investigated and the bacteria isolated were tested for antibiotic susceptibility. Of the various breeds examined, the incidence of otitis externa was highest in miniature poodles and cocker spaniels and Himalayan and Persian cats. The organisms most commonly associated with otitis externa were coagulase-negative staphylococci, followed by coagulase-positive staphylococci, streptococci and Escherichia coli. Most staphylococci were susceptible to the antibiotics tested, but 15 per cent of staphylococci were resistant to more than three antibiotics. Pseudomonas and Alcaligenes species were resistant to almost all antibiotics except gentamicin and colistin.