Couldn't get the Yahoo News link to come up for the story but I think he should lose his license since in taking that lazy approach in disposing of the bodies of the animals. I can also see the possible hazard of dropping the bodies off the side of the highway as it would bring in scavengers that would cause possible road hazards. Not only that but it's basically littering.
I believe that most if not all shelters, vets, and other places that deal with animals cremate the remains. To send it to a local landfill would leech possible disease into the water supply or into the circle of life with rodents or other animals coming by to feed on the remains.
