How many lives do dogs have?

If cats have 9 lives, how many does a dog have? Because, Ruckus has used one of his. We were in front of the house and Dan was racing his remote control car and having Ruckus chase it and having the car chase Ruckus. Sure enough, a car, (imagine that... a car.. on the street.. in front of our house) came by. Ruckus was down the street, too far to have him chase the remote car back to us in time. As he came towards us, the car came towards him, on the perfect path to squish him under the tires (according to my calculations) right in front of all the kids. As I was screaming and Dan was in the street trying to get the old man driving to stop, the driver hesitated and slowed enough for Ruckus to hit the edge of the front bumper.. tossing his hind leg up but essentially pushing him out of the way of the tire. Ruckus then continued running up the street to us and the car continued down the street. I think he is a little sore on his hind hip but luckily he is ok!