I don't really hope for any exhaustive information but thought I'd post. Out of a litter, we seem to have at least 1-2 who always go downhill with this strange thing and pass away. They are usually good eaters, though at all other times apart from eating they tend to be either fluffed up and standing head down or just sleeping with the head tucked under the wing. Age is about 3-4 months, mixed breeds (on the small side). The other littermates can be absolutely fine (though sometimes the whole litter seems feeling down) but one will begin to act this way. Now that I am more educated than in the beginning, as soon as I see young fluffed up babies, I immediately treat for Cocci with Baycox. Then the next thing is deworming with Ivermectin after a few days. I also give them extra food such as boiled egg, live yogurt, oatmeal, vegetables, with an avian enzyme added.......... NOTHING works - the bird just keeps eating (even greedily) and continues to fade away. The last one that passed away a few days ago got absolutely skin and bones and continued to eat until his last way. It is excruciating to see them suffer so badly and not being able to do ANYTHING about it. I need to add that we have indeed seen some respiratory thing going on (though these usually and ironically are NOT the ones affected), and also possibly Marek's (not proven by results but had several leg problem/lameness/death cases over the last year). However, the ones fading seem to have no other symptoms that I can think of. Has anyone seen this before? I am getting very discouraged - it's like no matter how much energy and effort I pour into trying to save them, nothing helps. I don't even take poop samples to our vets again because they always used to come back as "cocci" and we do treat for that immediately now. Thank you in advance for any advice or thoughts, I am really giving up at this point (but I can't really, and tomorrow morning I'll be boiling eggs and mixing their breakfast for them because while there is life, there is hope).