I shoot p-dogs and rock chucks because they are there and I have a gun. Its a blast blowing them apart. What can I say? I do use the excuse that I'm helping protect the ground, but basically, its fun. I must be demented.
Like Brian said, losing a deer does happen occasionally. There were hundreds and hundreds of thousands of deer shot in this country this fall and I'll bet that the ones that were lost and got away make up about 1/4 of 1 percent. With that small percentage it is completely useless to make a law requiring dogs.
Besides that, your dogs are going to run right thru where somebody is sitting and waiting for a deer. Then guess what happens?? Your dogs are going to be shot. Your going to be out a dog, you'll both end up in an expensive court and you still wont have a deer.