We have two Grey's - a 9 yr old female (Sara); and a 5 yr old male - both from a Fl track - retired due to injury @ 18 mo > 2 yrs. The male, is accepting to anyone and anything - the F on the other hand shows aggression with other dogs, and especially cats - outside - when in the house, there is absolutely no problem with my daughter's Papillion, and Chiwawa ?, or my son's Chiwawa ? when they visit. We have a chain link fenced in back yard, with 16 large oak trees. Just last week , we tried to notify owners of a young cat/kitten that was hanging around the back yard , looking for birds (that come to our bird feeder)- we found dead birds in the back yard. About a month ago , Sara treed the cat/kitten- it had an ID tag on it (which was hard to get , as it took time to get it down from the tree) - no luck. Saw same cat three days ago , notified a neighbour who in turn got in touch with the cat owner (Monday) - Tue. morning the cat was back , and unfortunately , Sara killed it - the comment from the owner of the cat was " we have been in three neighbourhoods, and the neighbours have complained about our cat, but she drives us crazy , wanting to go out". So, we have two families that were devastated by the turn of events - the cat owners were forewarned, they have young children that wouldn't know how to figure it out, and we too are devastated , in that we have a fenced back yard, the dogs are never off leash, and we always walk on the other side of the street when we see someone approaching with another dog. Also, my wife went crazy when she found a dead Jack rabbit at the foot of the deck stairs. We know who did it. KC