That is messed up. The sad part is you will probably be punished more then they will. Its not right. The laws are not always in favor of the victim. I can't blame you for doing what you did. If you would have killed him it would have been the easy way out. Now everyday that guys alive he will be messed up and have walking issues and pain. He gets to think about for the rest of his life. Karma will find its way back to him. I hope you don't get into too much trouble, and sorry about your dog.