There was no Yorkie weight chart back in 2005, we used the Chihuahua weight chart. It didn't work very well in most cases because the throwbacks could come from as far back as 10 generations ago. I have not done more research in the last 3 years and an updated search might find that the throwbacks could come from farther back. I was told that many genetic problems could be bred out in 10 generations but like I said above, that might have been disproved by now. Things change so quickly when you can have a new generation every year. Sylvia
Chihuahua weight chart