I recently bought a EE hen from a swap meet, and she is missing ALL the feathers on her back and the tops of her wings (roo damage I think). I want to worm her with some Ivomec Eprinex, but I don't want to irritate her exposed skin. Should I use less, say .3 ml insted of .5? I'm thinking that with fewer feathers to soak it up that much may be harmful, or ineffictive if I use too little. I would rather give too little, and then dose her again in 3 wks or so. I also wanted to rub some bag balm on her skin because it is looking kind of dry and chapped. Will that interfere with th Ivomec? Should I put bag balm on first, or after the Ivomec?