Introducing Staffordshire pup to his father

Question
My 5year old Staffordshire bull terrier (Tyson) has had pups and I have recently brought a male home to keep (Jr). I have introduced them both throughout the day with Tyson on a lead to see how he reacts. He has been fine and takes little interest, but I've recently let him off his lead to sniff around and interact with Jr closer. But he has been drooling heavily and losing fur more than I've ever saw him do. Jr wants to play but Tyson is not interested. There have been no signs of aggression from either dog but Tyson's behaviour is nothing like I've ever witnessed. Any advice or light shed on this matter would be much appreciated

Answer
For some reason his pup is really getting him anxious to a point that he has no clue how to handle himself. It's great that there has been no aggression at this point, so I think the main thing is maintaining a calm(er) setting until we know for sure his dad can handle his pup being around. And the best way to do that is through providing a mutual setting where both parties (the doggies) can be natural and it's a setting that you're comfortable acting as though nothing new and exciting is going on. Per say, the backyard. Remember, though, that even though you don't think you may be showing signs of anxiety, doesn't mean that Tyson can't sense that and the more anxiety he can sense, the more he is going to feel and portray.

I also want to make sure you are feeding separating and walking separately as well as together. This will give Tyson a sense that just some other dog isn't taking his time away and he still knows he has time with you. It also works at playtime/training time for the pup as well.

Let me know how things go.