I always let my chickens out in the am to free range all day. Well the other day was no different I let them out and took my son to his dr. apt which was a long apt way longer than I thought and it had started raining, I leave them where they can go under the deck for shelter in the rain and leave the coop door open, long story short when I got back home it had been pouring hard over an hour and all the chickens got in the coop but my silkie roo anad the coop doors blew shut and he was stuck outside. He was soaked to the point he couldn't stand up, I put him in dried him off and he seemed ok yesterday but today he is sick like upper respitory he can't even crow I have him on anti-biotics but could the rain have caused his sickness???
