denice.r - 10/30/2014 07:25 I have 3 guardian dogs, 2 pyrs and the short coated girl is a 3 way cross Tarta, Maremma, Spanish mastiff. They all were raised by me and have been around border collies all their lives. They accept the collies are there to move the sheep and either just move out of the way or tag along with the sheep. When they are young they do try to play with the border collies when they come into the pasture. Most of the time they are ignored because there are sheep to work. If the guardain dogs come into the yard all the dogs play together but they know Their Border collies and not so trusting of others. My mom has a little 10 lb rat terrier that the guardian dogs play with. It is pretty funny to watch a 80 lb dog run and play with a 10 lb dog that they could crush under a foot. They are very cool dogs, love their pack memebers - be it sheep, other dogs, people- but boy can they run off intruders. They will kill coyotes if they catch them. Is in incredible to see them go from standing still to alert and running full speed across the pasture in a second. I sure would not want one running toward me. I do know people who have had their border collies injured and killed by guardian dogs. Some breeds are more aggressive than others.