His tail is fine, it's just where his fur has thinned so you're seeing the natural direction of his tail now
.
He's got a bit of the old man scuttle going on, robos do tend to adopt more of a side to side movement as they age, but again the natural muscle wastage, and general weight loss make this more obvious. He is losing a little fur on his back there, but this can happen in older hams. As long as he isn't scratching so his dermadex mights are staying under control there is nothing to be concerned about. He looks like a happy little fella, and that he's doing well. Keep an eye out for any lumps or bumps, but as long as he is how he is just make a lovely fuss of him for as long as he has with you
