Hi. Sorry to hear that you old lad is struggling with an ear infection. We’ve had the same trouble with our boy, but we are hopeful that we’ve cracked it at long last - after nearly a year! Murphy had swabs taken on a number of occasions and it was pseudomonas. He also was treated with an antibiotic that the swab showed was suitable, but it didn’t clear up. A later swab showed that he’d become resistant to that one, so it was changed, but again it didn’t work. After some research on this forum, I saw that someone had had some success with a human antibiotic called Flamazine and I spoke to the vet about this. We tried it (it’s a cream so they have to make it into a suspension with saline) and after a month on this it actually seems to have gone at long last. There has been no sign of the pseudomonas for weeks now. Maybe speak to your vet about trying Flamazine. Best of luck.