Coming from an AP interview with executive producer Mark Rubin...

"There was a risk of shoehorning the dog into scenes where he wasn't originally going to be. Fortunately, that only lasted for a few weeks and everybody got back to concentrating on making the game. It's great that Riley is so popular, but let's focus on the game. Let's have Riley make sense and not just put him in space or in a scuba suit."

- Riley's battlefield perspective can be glimpsed through a camera mounted to his back
- he can receive orders to create distractions or take down enemies
- devs met with a retired Navy SEAL and his former military service dog
- German Shepherd Ruger and a smaller Belgian Malinois called Rico were motion-capped
- you may be able to spot the differences between the two dogs when playing
- Ruger and Rico were outfitted with custom motion-capture gear
- they originally wore special booties on their paws so dozens of cameras could film
- Rico provided the biting and tackling
- Ruger performed the movements
- it was a challenge to get the dog to perform as if it were in realistic locations

"Everybody thinks we're going to kill the dog. Maybe that's the expected thing we would do, so maybe it's not what we'll do? We'll see. People around here didn't know, and they had that same sentiment: 'We better not kill the dog.' The emotional investment for the dog here has been just as strong as what's happening out in the public."

Link