This can be done in co-op or single player.

When the dogs come, go to the big, main room (the room with the teleporter and the Juggernog machine).

When in the room go to the area where you buy the bowie knife and the Juggernog, and face the way you came in.

When the dogs come, you can sit by the Juggernug machine and shot the dogs.

The only problem I have had with this strategy is when on co-op, when everyone happens to reload at the same time and nobody is shooting the dogs - everybody dies!