Im a little concerned that my previously well balanced, well mannered dog has started humping other dogs now he has been neutered. He was neutered at 16 months, due to an undescended testicle and since then I have noticed this new humping behaviour BUT he will ONLY hump a dog when I am fussing it. Im sure he never did this before, but now it seems when we are walking and another dog comes up to me and I pay it any attention he will jump on it and start to hump. He has perfectly good doggy manners when he is playing with other dogs (when I am not in the equation) infact he is, and always has been, brilliant in that department. We walk in woodland that is very popular with dog walkers, we often meet 10 or 12 dogs on a normal walk (lots more at the weekend)...most are off-lead and we haven't encountered any problems when he meets them as we pass, he will often play with dogs his age or just pass by dogs that don't want to...but as soon as I say hello/fuss any other dog he will do it! Im SURE this has only started since he was neutered (a few months ago) I don't recall it happening before then...I didn't partcularly want to get him snipped, it was only because of the medical problems that I did...I am now feeling like I have ruined my perfectly well mannered dog! I know the simple solution is for me to never fuss strange dogs again, but I know many of the walkers and their dogs and I enjoy chatting to them and fussing their dogs as we stop for a bit. I mean I CAN just stop fussing other dogs if there is no way of working on this, I'd just prefer to understand why he is doing it, rather than just avoiding the situation entirely. He does not hump dogs he knows well when I fuss them, he never does it to our 3 year old bitch or our neighbours dogs that he knows well, doesn't bat an eyelid when I fuss them! What is making him do this all of a sudden?