[BoBoBird]

Hi, I need some advice on my sick bird
I'v come to the conclusion that i think he has some sort of respiratory disease?? I've taken him to the vets twice now. He's had 2 doses of anti-biotics, and some Avipro, which i think was to help with his diarreah (spellcheck?) It started with him not able to stand on his perch and falling. I put him on top of his cage to rest and all he was doing was biting at his feet as if telling them to work properly
He's very thin, though you wouldn't know unless you held/felt him.
He is eating and drinking ok. Though when he eats he collects some seed then jumps to another perch and tilts his head back as he sort of chews. His tail also bobs rythmically as he breaths.
He still chats away, plays with his toys, cuddles his mirrors.
So the problems are diarreah, tail bobbing, and tilting head when eating...oh and he also does that after he's drank some water. I've only noticed this since being to the vets, so i haven't told them yet...i'm due to go back very early new year....but i was just wondering if someone could give me some advice on here meantime????
Thanks in advance...anyone