[gemy]

You have gotten great replies so far. I would like to hone in on your other male dog though.

First you did not mention size of the dog, or the breed. Avoiding mating is a must if you have two un-neutered dogs in your home. If you are against neutering then I would get a male Yorkie. Then you have no worries, and there are plenty believe you me, if you have two intact opposite sexed dogs in the home. Most pet owners, are not prepared for what it takes, to keep un-intentional matings from happening.

So about your current dog. What is his temperament/character like? Is he prey driven? Is he obedience trained? Your Yorkie as a puppy is small and vulnerable, and can not play safely with a larger dog that is aggressive in their behaviour. One swat of a big dog's paw (even in play), can damage that tiney body. Most of the sighthounds would not be a good match, many of the field dogs either. Boxers unless a lot older and well trained are not a good choice with a Yorkie. Vizla's, Rhodesian Ridgebacks, nope.
This is generally speaking. Always know the character the disposition of the dog you currently have.