My husband got his first boxer from his sister because she was always so excited to see him, more than any other person. She would run to him as he walked in the door and pee on the floor in front of him all the time. When he left, she would sit at the door and cry and wait for him to come back. Finally, his sister said just take the dog, she's yours anyway, doesn't want to have anything to do with me!
:D
She outgrew the peeing when seeing him in a short time.
Also, a friend of mine has a Rottweiler that would do the same thing everytime I walked in the house. It got to the point that when I walked in, the dog would greet me and my friend would go get the resolve carpet cleaner and a sponge and hand it to me to clean up when I was done saying hello!:D
So I wouldn't worry too much. They just get so over excited.