http://www.dogaware.com/dogfeeding.html#addfood
The dog aware site says that the yolks contain plenty of biotin to make up for what the raw egg whites destroy.
Not really sure what that means but I guess it's fine to feed both.
I give eggs once or twice a week however one of my dogs prefers them slightly cooked while the other enjoys them raw.
Not sure if there is a better type to feed? I go with the vita free run but they do have the more expensive organic eggs.