i give brewers yeast to all of my dogs daily and it really helps with their coats. my min pin now rarely sheds, if at all. his coat is also a nice shade of red, as it should be
i think they are great
now...about bathing your yorkie...i have always heard once a week. i bathe maggie every friday
unless she gets into something, then she gets one in between too
but typically once a week.