I have a 3 year old male Jack Russell and he is a great dog. He goes with my wife & I 24/7. Work, home, boating, & traveling. He's been great and minds well. He has never tried to bite anyone (since his first attempt as a puppy which I put a quick halt to that behavior) including little children that crawl all over him and pull the ears. He's great with other female dogs, BUT when it come to male dogs he has some trouble. He moves right into the sniffing thing and sometime they get agressive. If another male comes to visit in our house he get really agressive about food and toys. He get so focused that he will follow them around and try to pick a fight. Even if the other dog is 75lb pit bull. (He's 15lbs and thinks he's a 100lb Pit Bull) He's not been fixed but he has an appt. for two weeks from now for the deed. (Poor Guy)
Question, is there anything I can do to break this or is that the nature of the beast. Now I yell, slap and break up the fight but that seems to do nothing for the next time. I have a shock colar I used in his training days but once he starts to fight he can't feel it and thus it does no good.
He's such a great dog I hate to see this side of him. he's 99% Dr. Jeckel and 1% Mr. Hyde
Any help would be great....
See attached picture,