Dead pullet, looking to know what happened to prevent from happening again

[jklhgyfhg]

I am a first time chicken keeper. I feel awful that I lost one of my pullets, she was a 4 month old Black Australorp.

The evening before I found her dead in the run I knew something was wrong, I had picked her up to check her over as usual and was stroking her silky soft feathers. I handed her over to my partner, and as soon as he had her in his hands, a brownish clear liquid came flowing out of her mouth and onto the coop floor. When he set her down, she stood still for a moment and then went over to a (lower) roost and perched there. I made a mental note to check on her again in the morning.
In the morning when I let the birds out she was the last to leave the coop, which was unusual for her. I had to leave for a few hours and when I returned she was laying dead beside a tree.

Her behaviour up until her last evening was normal, she was drinking plenty of water, eating normal amounts of food, loved foraging in the run and had a healthy curiosity and energy level equal to the other birds in the flock. I checked her and the others every day/every other day for mites or abnormal swelling. Was there something I missed?

I'm just looking for some guidance to know where my mistakes as a first timer were made and how to prevent them from happening again.
Thank you

 

[Wyorp Rock]

I'm sorry about your pullet.

It would be hard to know why she died unless a necropsy is performed. State labs will do necropsy for you or you can do your own informal one.

As for the spilling of fluids from the beak, she may have had a crop issue or the crop may have been pressed causing the expulsion of fluids. Chickens have no gag reflex, so they can aspirate fluids that come back up, that's a possibility, but you would have likely heard coughing or wheezing.