Do you have a picture of his tail? Are they that way because there was an issue with the shafting? Or is this due to breakage? If breakage, it could flock members plucking, space too small, or areas where the tail is getting damaged. Changing his living quarters might help. If it's an issue with the shafting, most I'd know to do is remove the shafting myself with a long fingernail, but at this point, it could be too late.
(I don't show, so I don't know of anything that'd help. Whenever I see an issue, I often just let it go because it's not bothering the bird, just its looks.)
