My chicken (over 3 years old) has been ill for over a week. She still eats, drinks and poops, hasn't laid any eggs since this started. When I picked her up, a putrid darkish drool came out of her mouth. Each time I have picked her up, the same thing happens (quite a bit comes out each time). Her equilibrium seems off a little, and her tail feathers are drooped. Anyone know what could be up with her? Thanks in advance!