Very late to the conversation, but I can suggest that you check for bumble foot. He may have a huge sore black spot under his foot. Start there because that's what it sounds like it is. If so, he needs to have that foot soaked until it is soft enough that it falls out and can heal. That sore progresses though and shows in how it makes their walk change. Check others too! Clean all your roosts too with very hot water and diluted vinegar. Hope he is better!We have a buff orpington rooster, about 3 years old, and he has always had a funny hopping kind of walk. We thought it might have been one of his spurs touching his other leg now and then that made him hop, but this last week or so I have been reviewing his whole situation. His gait is now so poor that I'm wondering if he's in pain. At times he overbalances backward and almost falls over and sometimes he crouches as he walks. And even when he's standing around he doesn't have that upright proud chest of other roosters. Can anyone advise?