Brown spots on tail

[Chickengeorge87]

Does anyone know what can cause this discoloration in the tail feathers both of his brothers don’t have these brown spots like he does i heard it can be caused by giving medication while the feathers are still growing not sure tho anyone have any thoughts?

 

[Chicken_Obsesser]

@Yard Farmer @NagemTX

 

[NagemTX]

Does anyone know what can cause this discoloration in the tail feathers both of his brothers don’t have these brown spots like he does i heard it can be caused by giving medication while the feathers are still growing not sure tho anyone have any thoughts?

It looks like stress while growing the feathers. Even the feathers structure looks effected.