Many people are not aware, but on March 24, 1998 a law went into effect to protect animals riding in the beds of pick-up trucks.  That law states the following:

Chapter 90: Section 22H. Transportation of animals in motor vehicles; safety; penalty.

Section 22H. No person shall transport an animal in the back of a motor vehicle in a space intended for a load on the vehicle on a public way unless such space is enclosed or has side and tail racks to a height of at least 46 inches extending vertically from the floor, the animal is cross tethered to the vehicle, the animal is protected by a secured container or cage or the animal is otherwise protected in a manner which will prevent the animal from being thrown or from falling or jumping from the vehicle. Whoever violates the provisions of this section shall be punished by a fine of not less than $50.

According to the Massachusetts Society for the Prevention of Cruelty to Animals (MSPCA), a statewide survey showed that 71 percent of Massachusetts veterinarians reported treating animals that were injured as a result of riding in the back of an open-bed vehicle while unsecured.

Generally, cross-tethering type harnessing devices can be purchased at a pet supply store for between $15-$40.  If you have trouble locating a store that sells this type of harness, contact your veterinarian for more assistance.