Beginnings of pasty butt, chick breathing hard - what to do?

[Branch Chickens]

I have a chick question for you. All of my little ladies are running around, acting healthy and inquisitive, except one. My little Blue Cochin seemed to have the beginnings of pasty butt yesterday, so I cleaned her up with warm water and soap and dried her off with a warm hair dryer. She also seems to be breathing very hard (and was before, as well), and her entire body moves quite strongly with each breath. I've tried watching her to see her poop (fun, right?), but I haven't seen it yet. Is there a chance that she is blocked inside? The vent and area immediately surrounding it looks good now, but I don't know if that pasting could go in further.
Other info...
She is my smallest chick. My other Blue Cochin had some pasting, but she seems fine now.
The brooder temp ranges from 95.5 degrees immediately under the light to 75 degrees near the food and water.

 

[Branch Chickens]

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[Branch Chickens]

In case anyone else comes across this thread in a search, I wanted to update to say that the baby chick passed, 4 days after she arrived. I don't know if it was related to pasting or not, but I'm sure her size had something to do with it. She was a standard cochin chick, but a very small one, the smallest chick we had.