Weird growth on chick!!!

[ssmith00]

Hi!
I have six new chickies and one has a weird growth on it. It looks like a huge water filled blister.
I noticed it looked like it has a bald bum area when I got them home. I sent a msg to where I got them (chicks were five days old at the the time) and they told me that the chicken just hasn't got all its feathers in and nothing to worry about...
Well about two days later I noticed it was losing more feathers and the spot is growing and is quite large now.
The other chicks all seem to be fine.
The chick is acting normal and doesn't seem to be bothered but has started having watery poops the last two days.
I am cleaning the area 2-3 times a day.
I have been looking on this site for a couple of days and can't seem to find anything similar...

Any ideas?! Please help!!!

 

[Yorkshire Coop]

That's a large fluid sac there and mushy chick disease jumps out at me. A yolk sac infection called Omphalitis. Please do check out the link below ~

https://www.backyardchickens.com/a/mushy-chick-disease-yolk-sack-infection-omphalitis

Good luck with your chick

 

[ssmith00]

Thank you!!!