CBS' hit drama "NCIS" is back for season seven, and ET's getting all the set secrets about the actors and their canine cohorts.

Michael Weatherly and Sean Murray invited us along as their characters were chased by dogs though an impound lot!

Weatherly joked about having canine co-stars: "Here's the thing, if we could do every show with some dogs and some kids, we'd be the number one CBS show. Unfortunately, 'The Mentalist' is always using the kids and the dogs and Hollywood only has so many, so we kinda have to take that number two slot over there on CBS."

Tune in to "NCIS" tonight to see where the cast's canine adventures take them!