I just checked on the chicks (we've been gone all afternoon again) and noticed that one of chicks appears to have a very dirty bum (all the others are nice and clean) so I picked her up and it seems to be possibly pasty butt? Or maybe just diarrhea? As you can see, the actual vent appears clean but very red. I just took photos of all the chicks late last nighr and it wasn't there and it was not there this morning either so happened some time this afternoon. I accidentally touched it twice picking her up (GROSS!) and it's wet. I plan on wiping her down either way but if it something else I want to know. And I'm guessing this needs to happen tonight and not wait? Plan to anyway but just making sure. They turn a week old on Monday and I believe she is currently the smallest. One chick had a neck issue but not this one and that one appears better and growing fast like the others, this girl is now the small one. I have 9, 2 BRs, 2 BAs, 3 BOs (I think, one is the free one), and 2 EEs. Pretty sure this little girl is one of the barred rocks. They are in a small kiddy pool with fairly high cardboard sides in the bathroom and MHP method. The window is usually closed but I plan on opening it during the day. They are moving to the garage this weekend though and hopefully a bigger brooder. They are on pine shavings and I have not changed bedding yet and didn't stir or do anything the first few days (I know, bad) but I did take everything out and stir/mix and fluff up the bedding yesterday. Also replaced the water first time yesterday (it was clean and they weren't drinking much. Am now replacing daily). I plan on fully changing out the bedding tomorrow and then adding an inch a day and changing every few days. Am also switching to paper and/or aspen bedding (bought both today). On Agway medicated chick starter and grower. And it smells up there which is a large reason I'm changing the bedding but we didn't have a scoopor anymore bedding to do it until today. All seem very healthy and active though but this one seems pretty sleepy last few days and falls asleep in my hands. Bedding and food seems dusty. I think the main issue is the lack of ventilation but could she have something else? And will she pull through if I clean her bum and change the bedding? Awful pics but she was moving and peeping. Bum is much redder than that. Oh and they are from Meyer's and vaccinated for Marek's and, again, on medicated feed.