He is a bit cautious, bordering on skittish when he meets somebody new, be it human, animal, or object, but once he got his guts up to meet "it", it takes him but 2 seconds to come around.
He barks like a hound, but his tail is sooooo loooong, it has got to be that of a Great Dane. I also see shepherd in him, so my guess are these 3 breeds: hound, great dane, german shepherd.
However, there are DNA tests available now that are around 50 Dollars...if I ever have that amount to spare and my curiosity gets the better of me, I will have one done to determine his exact breeds.