First of all I want to say that Yorkies are such social dogs and they do very well with other dogs. When we introduced our baby Yorkie to our Maltese who was 1 1/2 at the time, I was worried about them getting along and the Maltese going crazy and changing with the new addition in the house. He did nothing wierd except mark in the house a bit to let us know who was boss! There was a short period of adjustment but for the most part it was an easy transition. And of couse now they are best buddies. I did keep the puppy in an X-pen for a short time when we weren't at home more for her safety but eventually she too had he run of the house like her big brother.
I don't think two dogs are any harder than one and in many ways I think it's easier because they keep each other company. As you may have read in an earlier thread, we are getting a third one in a few weeks. Thankfully she's 9-months old and not a baby puppy and she is coming from a breeder who presently has 8 dogs in the house. While I am a bit worried about the inital transition period, I think it will be wonderful to have another one. So go for it girl! Two is ALWAYS better than one!!
Best of luck with your decision.
