dogs ears

Question
I have a golden retriever poodle mix Last summer he developed sores on the tips of his ear flaps that bled quite a bit. The vet prescribed some antibotic ontiment and it went away in a few weeks She said it was caused fro the lake he swims in He now does not swim in the lake and I see the sores coming back.  He flaps his ears quite a lot but I don't see any infection when I look inside.  He does have the same sores on the inner tips of his ears.  Do you have any idea what it could be.  Allison

Answer
Hi Alison
I wonder if it's not staph. Does he scratch at all? The flapping could be causing the damage and may actually be caused from a yeast infection inside his ears or another kind of infection. What do the insides of his ears look like? What does he eat?
Cindi
thanks
Cindi