My seemingly healthy 1.5 yo Marans rooster died suddenly this morning. He was fine 5-10 minutes before. When I went back outside he was struggling on the ground then died within a minute or two. No sign of attack or parasites. Nothing obvious stuck in his airway. His feet were white though & face was purple. Any idea what could have happened to him? He came from good Greenfire stock & had not shown any signs of illness or decline. The hens seem fine several hours later but I’m still worried.