Dog living behind me

There is a dog that lives in the run down house behind me.  He is uber-fit, and I wonder if he gets enough to eat.  I think he has American Bulldog in him, that really muscly very bouncy type.  If he is outside and he sees me in the yard he comes running and barking just viciously, and I say loudly "Hi Baby!  How's the baby today?"  I think he wants really affection so bad.  But his owners just yell at him and pretty soon he goes back inside or to the front yard.  I don't think they want their dog to be happy.  I am not a big fan of people.