Hey there, this is what you need to do. Take your dog to the vet, or a different vet, and have them CULTURE the ears. That is a very important part as just picking random antibiotics has clearly not worked. This will grow the bacteria and provide information of what antibiotics to use. What I usually find is the issue with chronic ear infections is at home care. With an english setter you will really need to make sure the medication prescribed gets in that ear. Don't use any at home products or make your own products. They will not treat a bacterial ear infection, and will just make your dog's ears more painful and thus more difficult to administer medication. Additionally, some dogs get really bad ear infections that they need oral antibiotics as well, and sometimes a regimen of multiple ear medications too. Unfortunately we live in a day and age of antibiotic resistance. Lastly, if your dog has chronic ear infections, there is always a surgical procedure where you can remove the ear canals (total ear canal ablation [TECA])
