Yeah, the dogs. Speaking of which, I don't recall seeing much of them in Salvation. Even if there wasn't proper infiltrator termies by then.
Cause they only thought of it in the fourth film? 
Yes, yes. Before I saw the film though, I was hoping that the idea would have already been implemented because it seemed a logical pair with the more humaniform T-800 infiltrator model. Though, I'm sure film and gamer minds differ in their wiring.
