I haven't noticed any issues with using it, but my girls are only 1.5 yrs old, so maybe as they age there could be problems? I don't put it in their food, just in their dustbathing area. I honestly don't know if it was helping or not, b/c we developed an issue with mites/lice. I started using poultry protector about every three months or so, and no more problem. Most people have told me that mites/fleas/etc are just a part of having chickens, and as long as you don't get an infestation you should be fine. I did know that you aren't supposed to breath it in, but never really thought about it with the chickens (which seems a little careless, in retrospect). I will probably do some more research into it before I make a final decision. I've been using it around my bunny hutches to help with fleas too, and my rabbits have never had any fleas that I have noticed. With the rabbits, they aren't in direct contact, just around the perimeter of the hutch. I do think it helps cut down on the fleas in particular, but obviously don't want to keep using it if it's hurting my animals.
What exactly IS poultry protector?