I think a puppy who is in your home to stay is different than a visitor or meeting other dogs outside.
Since Rasta gets along well with Roxie, that is an indication that Rasta does not have a serious problem with other dogs in general.
Max was an only pup until he was a little over a year old. When we brought home his brother, we had a few jealousy issues to iron out, but they got along very well from the start.
__________________ Kristin, Max and Teddy  |