One of my 7 month old roosters has been off balance today. I am not even sure how to describe this. He will be moving along just fine, then start bobbling and then recover. He has not fallen over yet. I saw him do this 4 time over the course of a few hours. The rest of the flock seems fine. In fact, he seems fine otherwise. His eyes and nose are clear, his feathers look right, he is eating and running around, crowing as usual, feet and legs look good, nothing odd at all besides this wobbling. He has been vaccinated for Marek's (along with the rest of the flock). They free range a few hours a day and I was thinking he might have eaten something poisonous, though I wouldn't know what. He and one of the other roos have been fighting a bit, maybe he got a good conk on the head? Anyone have a list of differential diagnoses for a wobbly, off balance, cockerel? Mine so far is: virus trauma to head trauma to leg poison anything else? How can I tell which it is once I have a list?