Someone posted a scan of some later chapter and it look like Babu was kinda alive but Chihiro tried to put it out of it's misery.
And he wasn't feral because of the owl, he was already feral a little before that. The owl was programmed to stop any zombies that's in an excited state that can do harm so it instantly attacked Babu.
I hope. Rea's effects is progressing slower but she is showing symptoms and her body is still rotting right? But like they said in the new chapter, she could be a new breed so I'm hoping for a non-tragic story...it's too sad..her life was kinda screwed up before, a happy ending would be nice to see.