Roo not walking Please help

[MartaKuz]

Hi everyone, I have a problem with my silkie frizzle Roo LuvRBoy. he hasn't been walking much. just noticed it last night. his tail feathers are down. So far I have given him poultry boost, and nutra drench and sequestered him. does anybody have any thoughts for me? I love this guy. he has produced so many gorgeous babies and he is literally the sweetest rooster I've ever had. He's only 3 years old. lots of life left in him. would really like to fix him up and help him feel better.
I've been trying to upload a video from my phone but backyard chickens won't let me

 

[MartaKuz]

And if anybody can teach me how to post a video I can show you what's going on

 

[Eggcessive]

The best way for us to view a video is to upload to YouTube with a link posted here.

 

[Silkiebegins]

He's probably sick with something. I would isolate him.