sleeping standing up

My young rooster (about 4 months old) is suddenly very lethargic, falling sleep standing up where his head will just tilt into the ground, and his tails feathers are down. His comb and wattle are also pale. He ate food this morning. I had this happen to another rooster about 4-6 weeks ago but...

Help. My 2-week-old golden penciled hamburg was listless and sleeping standing up for 24 hours or so. She also didn't grow at the same rate as her flock. She was not drinking unless I spoon-fed her. She died 48 hrs later. All my chickens were vaccinated from Coccidiosis and Marek's. I read...