Hallo Mari, nice to hear from you, but sorry to hear about your poorly pooch. Milo had this when he was about ten years old, he got an infection in both ears, oozing pus, it was horrible. He had antibiotics , and his 3ars flushed, which cleared it up, and his staggering too, but over the next few weeks he lost his eardrums and went deaf. We had to clean his ears every day for the rest of his life (he lived til fifteen), and put drops in them. He had to have his ears flushed under GA about three times subsequently, but the injection did not recur, though it was so sad that he went deaf. We watched his ears like a hawk (apparently his ear canals were very narrow). There was talk about the vet doing a total ablation, but after discovering what a massive op that was, and talking to a friend whose dog had it and was never the same again, we decided against it, and we were able to manage his condition until he died of something else entirely.
Hope this helps and your dog improves quickly.
Lesley