My 5 year-old rooster is now inside of our rehab cage in the garage away from the coop. He has always been ornery and aggressive to others, and would rarely charge and try to stick me. He has calmed down over the years after being dethroned from the head of the flock after running the roost for two years, but he earned his name, Brute-Roo. Yesterday I got too close with the watering jug after refilling it and he charged. I swatted him as lightly as i have in the past, which isn't forceful enough to knock him down, but he immediately started jumping, running backwards, and eventually fell on his back with legs splayed. I thought I had broken his neck and they were nerve spasms, but noticed he was still breathing, with closed eyes. I rubbed his belly and talked to him for around half an hour before rolling him over. He didn't try to stand but immediately rolled forward and wouldn't correct himself. We sat him back down and watched for a while. He seemed alert, was breathing normally, and eyes open and scanning everything. Now thinking he had just been dazed we went inside. Less than an hour later I found him on his back about 10 feet from where we left him, legs slayed to either side, but still breathing. We moved him to a cage in the garage, wrapped in a towel, and syringed some fresh water with a rooster-booster vitamin and electrolyte mix until he wouldn't take any more. We left the heat lamp on him after adjusting the height multiple times and checking his temperature. Today he was alert, had drank about half a cup of fluids, eaten a small handful of feed with a very light sprinkling of scratch, and tonight ate half a scrambled silkie egg, all on his own. He had moved around the cage and kicked half the towel off, but we are scared to fix it as last night any time we moved him he would try to stand and fall forward with stiff legs. The vets from each town surrounding us don't accept birds of any kind. We are really worried and hope he makes a full recovery, and are committed to giving him the best treatment we can. Open to suggestions or any thought to what has happened. I don't usually cry for our animals but did for Brute. His brother and himself are the last of the first 4 chickens we ever got, having lost the other rooster due to unknown illness in a friends yard (we lost every one of those 20+ birds a couple years ago with no explanation), and our best laying hen last year due to a tumor on her belly. Side-note: Last night before we gave up trying to get him to stand, I tested his neck movement by holding him by his torso and rolling his body left and right, up and down. He kept his head level through all of the movements (which I always thought amusing in the past, but was reassuring last night), so we doubt his neck had sustained significant injury.