There are many states that do not have laws currently in effect that prohibit driving with unrestrained dogs, and these states include: Alaska, Arkansas, Colorado, Delaware, D.C., Georgia, Idaho, Kansas, Kentucky, Missouri, Montana, Nebraska, Nevada, New Mexico, South Dakota, West Virginia, and Wyoming
But many of these states do have laws about punishing those who practice cruel and inhumane methods of transporting animals, and you have a chance of getting a distracted driving ticket if the unrestrained animal is thought to be a distraction to the driver.