I am out of thousands of dollars with no success. The next step unfortunately is something not too great for the dog and heartbreaking for me. Chronic ear infections sometimes need corrective surgery to open up the dog's external ear canal. In my experience when cleaning and antibiotic medication does not work, you need to look at the dog's diet. Adding a multi-mineral and vitamin supplement, plus one teaspoonful of flax seed oil and also making up your own homemade recipe of dog food from natural ingredients may help.
Some ear problems seem to be related to food allergies and nutrient deficiencies.
Good nutrition is the cornerstone for health, coupled with regular exercise and love and understanding. A healthy puppy does not need special herbal supplements like echinacea to boost the immune system. Avoid stress, such as noisy and rough children, and be mindful that the puppy's immune system is weakened for some time after the puppy has been vaccinated. Sometimes bringing an additional cat in can cause conflict in the social structure that has developed. So approach with caution and consider adopting a healthy young kitten who will hopefully bond with the young newcomer so that you will have a happy family of four cats.