I have read a lot about the raw diet and all the information is positive especially for those with allergies.  I have even found vets who swear by it!!  But there is a lot more to it than just raw beef - you do need veggies and other stuff and bones.  Yes bones!!  As long as bones are NOT cooked they are fine and actually GREAT for their teeth - you won't have any plaque problems.  The only problem I have with going raw is I worry about us humans with the potential for problems with cross contamination - especially with yorkies because of the long hair and getting it in there and then spreading it around especially since I have kids.  I would suggest calling around to vets you are likely to find many who still say it's a bad idea but when you find the ones that love it you will hear some amazing stories!!  Also do a search on line and you can find all kinds of information!!!!