i was talking to god (the opposite of dog) and he said that dog was used to following his commander's orders and listening to his master which leads me to think (how he said it) that he used to be in the master's army. Anyone else come across this thought?

Yes that's about it. If you haven't passed the DLC i can't say much more because of spoilers but yeah man your line of thought is correct

don't need to worry about the spoiler thing because first of all this is the spoiler section, and i already completed it . but thanks for clearing that thought out for me.

Oh i see >_< You are right tho. He was basicaly brain washed to be Dog. A servant and just that. That way he couldn't turn back on his master.

Yes.

The reason why he serves Elijah without question while he's Dog is because he's always bound to a master, the first being The Master from Fallout 1.