RIR will be 3 yrs in April. Last few days she's been withdrawn, comb layed over, fluffed. She will run out of the coop and trip and fall. This morning she ran out, trip and fell and stayed down. I picked her up and put her by water and she drank a lot. I put probiotics and electrolytes in their water 2 days ago, also fed her yogurt with sunflower seeds and oatmeal. Brought her in house this morning after she wouldn't get up. She has been sleeping for an hour now. HELP! What do you think it is??