Rooster can't walk. Any advice

[CDennis]

My Maran rooster can't walk. Yesterday he was just having trouble and unable to get footing. Today when he tries to walk he falls on his head. I looked all up and down his legs and I don't see an issue but I am far from a chicken injury expert. I wasn't sure if he had been drinking so I dipped his beak in some water, I also put food in front of him but no he didn't eat. He is a pet not a meat bird so if there is anything I can do to help him I sure would like to. Any advice on what could be causing this? How to give him the best chance? Or if he is beyond help and needs to be culled. Thanks!