I have an AKC registered Cocker. Since we moved to TX she has had an on going problem with ear infections. Even with dog insurance we paid out around 500 bucks fighting them. The infections are primarily yeast infections. My wife found a way of letting the ears air out as they were being treated. If your Cocker has enough hair on ttheir ears you take a rubber band and attach the ears together at the back of the dog's head. Keep the ears up and the ears dry out in a couple of days. The dog is not bothered by this except when the  ears fall over the eyes and they overcome that pretty quickly. A rubber band sure beats numerous medicines and for sure beats surgery! Good luck. I will be posting messages for dog lovers in southeast TX soon