I found my rooster this morning unable to get up. I can't feel any injurys and he was fine yesterday. He is 17 weeks old. His symptoms are, leg paralysis, open mouth breathing, stretching his neck then his head will collapse, body twitching. His eyes look normal. I have him separated with food and water close by. I will attach a video of him. Does any have any idea would could be going on with him? Does this look like mereks?