Rocky is a 6-ish year-old large fowl light Brahma roo who we have had since he was an egg. He is about 15 pounds. He has had a very slight limp that comes and goes for about a year now. The etiology has never been found - no bumblefoot, no sores, no obvious injury. He has never roosted, always sleeping in a corner of the coop with a couple of his girls. Last week, we noticed he has been walking less. He would get up, take 10 or so steps, and then squat back down. Now he is only taking about 5 steps for the last 3 to 4 days. He will stand up and stretch, stand up to crow, and stand to eat. He walks like he is having trouble bending his "knees." When he lies down, his legs are under him, not sticking out in front or back, he just squats on his haunches (do chickens have haunches?). He is eating fine and poop looks normal. I have been giving him extra protein in the form of mealworms and vitamins this week along with his usual flock raiser. He loves raisins. We caught the our alpha roo attacking him on Monday, which of course didn't help, but we now are keeping them separated. Rocky is no longer being attacked by any of the other chickens as he is being sequestered in a run (and in the house at night). Is this old for a large roo? Do chickens get arthritis or strokes? Any ideas/suggestions?