Sorry your hen isn't well.
DE in the food is completely irrelevant and used by many companies already... approved for use as an anti caking agent up to 2%. But proven ineffective at internal parasite control.
Why worm if the other birds was confirmed to not have worms? Worming an already ill birds can just push them over the edge.
You have an awful lot of supplements going on... but what are you feeding including treats?
When was the last time you saw eggs? How is your weather? How old are your 3 new babies and where did they come from and how long have you had them?
I hope it doesn't go that far... but if you lose another hen I suggest getting a necropsy done to determine cause. Here are links to help achieve that...
https://www.backyardchickens.com/threads/how-to-send-a-bird-for-a-necropsy-pictures.799747/
https://www.aphis.usda.gov/animal_health/nahln/downloads/all_nahln_lab_list.pdf
Alternatively, they are getting that age to start seeing things like internal laying or reproductive issues.
Milk thistle ... I think is supposed to be like an anti oxidant for the liver maybe?? How long did it take from symptoms to passing on your leghorn?
Sorry for your loss also.
Hope you get answers and your hen recovers quickly!![]()


Even here on BYC, and YES even from me... I suggest ALWAYS getting a second or even third and fourth opinion. Some people are simply repeating what "hear say" they have read and don't bother looking for facts. Even the popular fresh eggs daily website, Lisa chooses to spread lies to thousands of readers instead of getting fecal floats. I NEVER just treat without testing... to prevent treating for what I don't have and not treating for what I might have. But also to prevent resistance from said parasites. YES, test can be wrong. There can be some load that isn't yet heavy enough for detection. I just learned it is suggested that you do a second test two weeks later (after negative). That is fairly cost prohibitive to me. So I bought my own microscope stuff, but haven't yet gotten there. Also, we are all doing our best until we learn something new. Then we switch it up if we can. I have given incorrect information, but by the time I learned different was too late cuz I can't figure where to go back and change it since I'm all over the place and it's easy to get lost in too many threads.
Worming a not ill bird should be fine and safe in MOST instances. But an already ill bird is a whole other story if worms isn't their issue... since it is essentially a mild poison.
