In a way, him being itchier has made me sure I didn't imagine the improvement.
Have you had any experience of dermoscent? I know somebody with a collie with a more severe skin problem that has used it in conjunction with a change of diet and it has made a big difference. I'm slightly cautious about adding extra calories and fats to his diet because we have lost cockers to pancreatitis so this seems like an option. Possibly for Brodie too?
Also going to start a diary with what he's eaten, where he has been etc to see if we can spot a link and stop my dad from cheating. (he swears he hasn't)
If the diet doesn't help, I'm going to get in touch with his breeder. They still have his dad and grandma so may be able to suggest if there is anything hereditary.