My Buff Orpington is very lethargic and is having trouble balancing. Comb is red, I’ve checked and always do for any skin issues, insects, etc and nothing. Checked internally for a possible broken shell and nothing. She hasn’t laid in a few months. She is 8+ Years old but was fine 10 days ago. Poop is green/yellow  and runny. I haven’t had an internal parasite issue that I can tell, and that is something you would know through symptoms I think. 
No other symptoms that I can see at all. Ive had hens and learned so much over the years and cannot figure this out. What do you think is going on?
	
		
			
		
		
	
				
			No other symptoms that I can see at all. Ive had hens and learned so much over the years and cannot figure this out. What do you think is going on?