Hi there,

Is there any discharge (if so what colour, thickness etc), is it just on the outside of the ear or also comming from the inside, swelling, other discomfort in other places in the dog?
You can start with Tea tree oil . Put a few drops in a tablespoon of olive oil and rub this (gently)on the ears. If the infection is also inside the ears than apply a few drops inside the ear to (you can warm the oil before, make sure it isn't to hot) do this 2 to 3x daily.
I also googled this http://www.dermapet.com/prod-09.html I have never used it (this is the first time I saw it) but it sounds like a good alternative for this problem.

Mirjam