Nothing against the 2 solutions already posted, but there's a easier way without them attempting to attack you. Completely hassel free.
If you are on your Veteran playthrough, this is potentially the best way to achieve this. This method, if followed correctly will allow you to knife 3 dogs without getting attacked with a very close checkpoint.
Similar to British Bleepers solution - same dogs but when you first come across them instead of alerting once in the church
Mission: All Ghillied Up1)
At the begining of the mission you'll come across 2 enemies patrolling outside a building, kill both of these. (Do Not Alert them)2)
Follow Macmillan to the window. you will see a dog on the sofa through the window, as well as 3 enemies inside. (Do Not alert them)3)
Follow macmillan around the building and wait, kill the guy when he stops by the car.
Look to your left and you'll see a very small square window, line up the two soldiers heads for a one bullet kill and head towards the door.4)
Wait for the other soldier to head towards the back door and headshot him. (if he goes towards the door where you're standing reload and stand a little further back)5)
crouch into the building, directly infront of you is a room with 2 sleeping dogs, knife both of them and then go and knife the one on the sofa. (which is alert but will not attack)6)
Reload the checkpoint and repeat. (checkpoint for me was just after killing the guy by the car)
This will also unlock:
Tested and completed on Veteran.
- Spelling Mistakes
- Updating links due to site update