I would keep the dog's on a leash and introduce them one at a time. If you have a head halter that works great. When introducing Nova to my sisters puppy I put her head halter on, and as I suspected Nova went to bite him, but I had full controlle over her head so she wasn't able to.

I also have introduced Nova (not sure how old she is) to Sada, who is a kitten. They got along great. I used the head halter though.

Ash