We have a golden lab that we got at the end of may. He's is about 2 and previously lived with 2 gsd. A first he seemed fine with other dogs a little overly pleased to see them but no problems but when walking etc we had only encountered medium to large dogs, he doesn't go off the lead as his recall isn't reliable but does have a flexi lead.
About 2 weeks after we had him my husband was walking him and met a neighbour who was walking her dog and friends, the friends dog was just friendly saying hello when her cairn terrier ran over and started biting at his chest then the friends dog joined, apparently she didn't do anything to stop it just stood there going omg he has never done this before etc. this dog now goes absolutely ballistic when they see each other but have never met when the terrier has been off the lead again.
Lots of other terriers seem to go ballistic barking their heads off when we pass and I'm not sure if this is normal terrier behaviour or a dislike of my dog.
A supposedly friendly lab went for him the other day when they were both on leads.
Finally today I was walking round the village green and my friends dog who a jack Russell( who we have only ever met on the lead before with friends husband and has barked but she has always said her dog. Is very laid back etc) bounded across the green and started nipping at mine.
My dog hasn't been neutered and I'm not sure if the other dogs sense this and asserting their dominance, would neutering stop the attacks for supposedly friendly dogs.