I am hoping to get some ideas to deal with a sporadic problem that I have with my 2 yr old GD. I read below about on leash aggression, but our occurs off leash, maybe once a month, depending upon circumstances. It never occurs between my dogs, she is 2nd to my 3 yr old, just with a few other dogs and never on leash. She is sweet to all people and usually all dogs. One example would be a month ago, when we were having dinner at friends (3 GDs, 1 lab and 1 pug), she would growl when the sweet pug (i've known since puppyhood) would approach to sniff her butt). Shelby would turn and growl. Bella didn't react at all to the growl. I would correct. If not corrected, Shelby would try to move away from Bella. She never confronted.
Then we have my neaighbors, who occasionaly would have their daughters boxer over. The 3 dogs play ball in my yard and are usually fine. Once in awhile, Shelby will growl at the boxer. Sometimes when she doesn't want the boxer to approach my neighbor. (Shelby loves my neighbor). Last night, Shelby (suddenly, according to my husband, husband and neighbor were standing right there) growled at the boxer. The boxer growled back and they went up on their hind legs and growled and made lots of noise. No biting occurred. My husband got Shelby's attention and pulled her away and brought her into the house.
This behavior has been hard because it is so sporadic. Even with the dogs that it happens with. Shelby had been playing with that boxer every day or every other day for the last week and a half. My neighbors are keeping the dog for their daughter for the next 6 months. Any help is appreciated. Shelby has been to training. She will go back and do some more starting next week. She attended doggie day care over the winter and did great by all accounts from the workers there.