Chicks behind pulsating

[Rosieposie6]

Howdy just seeing if anyone has seen this and possibly knows what’s going on
My brother recently got 9 chicks from a hatchery well all of them seem to be growing and doing fine except one. She’s a lot smaller than the others so possibly a different breed but her butt/back area is pulsating constantly. My adult hens do that before they lay but obviously this is a chick any possible reasons? Pasty butt?
Brother said she’s eating and drinking fine I asked if she pooping he wasn’t sure cause he has them all on the same brooder but don’t want to remove her because she could get cold. Any thoughts on what this could be or mean? Also we aren’t sure what breed she is I attached a picture below

 

[coach723]

How recently did he get them? Has she been doing this since she arrived? Have you seen signs of pasty butt, droppings around the vent or stuck in the fluff near the vent? It could be constipation and difficulty passing droppings. It would be good to know if she is pooping and what it looks like. You can give some chilled coconut oil to help with constipation, freeze or refrigerate a tsp and break it into small bits and feed them to her, see if it helps. You can give that throughout the day, and repeat daily for a bit to see if it helps. Shipping stress can be a factor. It's also possible that she has an internal issue that is affecting digestion, that could be something that didn't develop quite right during incubation. If she's not absorbing nutrients then it could be why she's much smaller. Sadly, some chicks do fail to thrive for unknown reasons.

 

[gimmie birdies]

From eating wood chips, cannot poop.

 

[Rosieposie6]

How recently did he get them? Has she been doing this since she arrived? Have you seen signs of pasty butt, droppings around the vent or stuck in the fluff near the vent? It could be constipation and difficulty passing droppings. It would be good to know if she is pooping and what it looks like. You can give some chilled coconut oil to help with constipation, freeze or refrigerate a tsp and break it into small bits and feed them to her, see if it helps. You can give that throughout the day, and repeat daily for a bit to see if it helps. Shipping stress can be a factor. It's also possible that she has an internal issue that is affecting digestion, that could be something that didn't develop quite right during incubation. If she's not absorbing nutrients then it could be why she's much smaller. Sadly, some chicks do fail to thrive for unknown reasons.

Yea I’m thinking the same that she’s smaller for a reason cause she came with assorted chicks like Ameraucanas, olive eggers etc and they’re all growing except her. I’ll let my brother know thanks for the advice! Much appreciated!