urgent scared and dont know whats rong

[bornnraised]

i have a hen thats 22 weeks old now and for the past few weeks i have been letting them out in the morning and this hen keeps loosing a tail feather each day is something wrong with her or does it mean something. also this morning i woke up and she has no tail feathers

 

[five is my dog]

the others may be pulling them out i would separate her just in case.

 

[bornnraised]

thxs