as soon as you said he walks backwards I knew he was a silkie. My friend has one and he went thru the whole bit , walking backwards , doing sommersaults, plus he had spells where he was so feverish she said he was hot to touch, and he had seizures. She put him in his crate when he did so he wouldn't get hurt thrashing around. I'm sure he was one that would have benefitted from prednisone but, she wouldn't go to vet. We all thought each day was his last one, I don't know when the turning point came but he is 3 yrs. old now. He has turned into a very good, protective roo - shows the girls where food is, lets them take food out of his mouth, etc. She did the polyvisol infant vitamins drops (NO iron), vit E, etc etc.
I am wondering if his problems stem from "shaken chickie" syndrome like they have with kids. It also causes rupture, brain damage etc. What does the seller say about it? I mean, you don't know if he was sent in this condition. Maybe he crowed in the box because he was so uncomfortable or scared. Is the seller someone you know, and trust.