Please help! Rooster gone back downhill!

[HenriettaRedHen]

I put a message on two weeks ago as my rooster had gone lame with bumblefoot. I treated him and got him back on his feet and with two lady lady friends doing a bit of ranging. He was fine yesterday, but today he cannot stand and has even taken to lying on his side with his legs stretched out. There is no heat in his legs and feet to indicate infection and he is eating really well. Has this happened to anyone else or does anyone know what I can do?
Thanks.