The type of infection must be identified by the veterinarian by examining a sample of ear exudate under a microscope, since bacterial infection will only respond to antibiotics, fungal infection to a fungicide, and ear mites to an insecticide.
The type of ear infection must be identified by the veterinarian through microscopic examination of a sample of ear discharge, as bacterial infections require antibiotic treatment, fungal infections necessitate antifungal medications, and ear mites demand insecticide application.