Zymox treats bacterial and Yeast Infections. ZYMOX-E has been designed to be used without other cleansers or medications, and should be used by itself. Contains natural enzymes and 1% hydrocortisone.
Otomax is indicated for the treatment of ear infections associated with yeast or bacteria susceptible to gentamicin. Need to clean ears well with cleanser prior to treatment.
The problem with ear infections is that they can be bacterial or fungal in nature. If you put the wrong medication in the ear, you can actually do more harm than good so you want to be sure of what you are dealing with before you put anything in the ear.
Let me know if you still have questions.