Hank & Dozer meet for the first time - but... [[Updated]]

So, my boyfriend brought Dozer over to my house today just to surprise me, because he had always said he would bring him, but didn't think he would, but today, he did. :) So, Hank and Dozer met.. Dozer was very friendly, but, he was the first dog that Hank was NOT happy with. He was very mean, actually. I never thought Hank would actually go after him if Dozer sniffed at him or wagged his tail at him, pawed at him to play with him. Hank did not want to play at all. They both were okay within a distance, but it seemed like Hank had a major problem with Dozer for some reason. Dozer is going to be 6 years old, not neutered, but Hank is neutered. Is there a reason? It's too bad they do not get along, but Hank gets along just fine with the neighbor's dog, which is a female and about a year old. Eventually Dozer was actually afraid of Hank, we had to put him in the cage so Dozer would come inside and go out in the front yard when it was time for Mike to take him home.

Any explaination?

Aww... naughty Hank!

It sounds like Hank might have been feeling protective of his home, and his family, particularly with an unaltered boy. Lots of neutered males tend to pick on intact males. :p Probably jealous.

I would try to introduce them next time on neutral territory, preferably a park, or somewhere that they can either be off-leash or on long lines so they can do the natural meeting ritual instead of meeting face to face. Try taking them on a walk together, side by side. Parallel walking is one of the best ways to introduce dogs.

Thank you!

I do think it is all pure jealousy. Hank seems to get very jealous if I am petting another dog, like for example, the neighbor's dog, Butters. She is that female dog I mentioned in my first post. The thing is, Hank just gets in the way or forces her out of the way so he is in between us. He will continue to play with her as he has her attention, not mine. I am assuming he was not a happy dog when Dozer came in the backyard, so that made 3 dogs. He just gets very jealous FAST.