I have a flock of 12 week old light sussex crosses. So far this week 4 have died!! Symptoms are tail down, eyes closing over like sleeping, there eyes also look like they are cross eyed, dropped wings. They are all a good weight, have shiny feathers and are eating and drinking well. I have another 2 that dont look to good tonight, both have the cross eyed thing!!! They are free range and fed on grower pellets, some corn and grit have access to clean drinking water and have very clean housing!!! The vet when i spoke to him today was not much use!! Have been on every website looking at symptoms but every website is differant. Is meriks a really common disease and how easy can birds get it? Any advice would be fab.