The dog wants the chickens as chew toys (part lab, soft mouth: bred for carrying and scaring birds, not killing). He leaves tomorrow, my parents agreed to take care of him for two weeks -_-" without the hen's or my permission.
UPDATE! Gamma is hanging with her flock again. She is eating, drinking, and taking care of herself. She still isn't running and not peeping or squawking loudly, but otherwise she seems like a normal flock member.
Thank you

Until the dog leaves, the chickens will remain in their coop.
Here's what happened: I was holding Flutter by another door, when my friend came out and didn't close the door all the way. She asked if Flutter would dare to go inside if I put her down, so I gently placed her on the wood porch. She commented on how Flutter was half-peeping and half-squawking (they are 2 months old) so I said "Oh, she does cluck." and bent down to pick her up (they cluck loudly when you pick them up, especially Flutter). As my hands were a few inches away from the hen, the dog came darting out. I didn't know he could get there, because I thought the door leading to the hallway was closed. I scooped up Flutter and held her close to me and high out of the dog's reach. Luckily, he (the dog) was too entranced by the peeping Golden Buff in my hands that he didn't notice the other three chicks pecking just out of sight. We were yelling the dog's name as my friend grabbed his collar and dragged him back inside. The yelling startled my siblings and my father, and one of them (idk who) left the back door open and rushed for the door we were at. Right as we closed the door we were at, I (still holding Flutter) went to the back lawn and saw the dog darting after the other three hens. My dad was chasing after him, so I know if I tried to get him I would only get in the way, so I ran as fast as I could towards the other hens and watched as he grabbed a chick (Gamma) I ran after and Poppy trying to catch her as my dad leaped on the dog, making him yelp and drop his catch. Gamma streaked towards the coop after that, squawking. My dad dragged the dog inside and closed the door and I put the chickens in the coop and proceeded to treat them for shock and check Gamma for injuries.