One of my chickens has been plagued with mites. It's obviously draining her and it was suggested in another post that giving her vitamins might help make her less susceptible. I've treated w/permethrin and DE and am going to get some ivermectin. She seems to be growing more slowly than the other 2 girls (probably a result of continual mite infestations) so I'd like to give her a helping hand. I'd appreciate any information on what to give her for vitamins, how/when/how much to dose her, and if the other 2 girls should/can get some also. Thanks.