Birds affected: None of the birds are younger than 1 week or older than 2 months who die. 5 different breeds in 3 seperate buildings. Birds came from 3 different sources(vaccinated Murrays Hatchery boilers, Goldfeather Farm, my own hatches.) Symptoms: They show no symptoms then suddenly become tired and die within an hour. About 50% of affected birds seem thin. About 40% are pale before death. All become sleepy and limp, progressing to stretching and twitching then death. Any attempt to drink water and the bird dies immediately. Things NOT happening: No adult birds affected, no poopy butts or other vent area issues, no blood in stool, not gone off feed or water before onset of illness, no wounds or injury, no mites or external parasites seen, no predator involvment. Not overly hot, chilled, wet. Not picked on by other birds Things I've tried: Cleaned the out pens, added new bedding and lime. Treated with metronidazole one week. Wormed with Wazine. Bleaching waterers several times a week. Adding apple cider vinegar to water. Moved chicks under 1 week old into house with no improvement, burn the dead birds Possible contributing factors In same time frame: abrupt weather change to cold and rain, 4 batches of chicks arrived from Goldfeather farms, Death of best hunting cat resulted in noticable increase in barn swallows and mice within a week. Things that happened one week after chickens began dying:house cat diagnosed with Giardia and quarantined to sunporch of house, cat never had been outdoors or in contact with the birds.One barn cat sick with diarreha and immediately quarantined. Young kitten died of vet diagnosed heart ailment with similar symptoms prior to death. What the back is going on here? There are so many possibilities that come up on Google it's overwhelming. Has anyone had a similar problem?