Lack of early socialization does sound like the culprit here, slow socialization and introduction is probably what you need. If your friends large dogs are well trained maybe you can try putting them in a "down" position next to him, its a submissive position. Then let him sniff their butt first, even though Chip is very well socialized when he meets large dogs for the first time he likes to be the first butt sniffer otherwise if the big dog does it first he gets a little growly.
Have you tried doggy time outs when he has done this? Then when he has calmed down try it again, and repeat the time out if necessary. |