Source: http://www.aspca.org/Blog/cruelty-alert-dogs-in-pickup-trucks

When you drive with a loose dog in the back of your truck, you're taking a huge risk and placing your dog and other motorists in danger," says Chuck Mai, a vice president with AAA Oklahoma. "Even if a dog is trained, we're talking about an animal who responds to stimuli on impulse. This irresponsible decision can start a deadly chain reaction on the road."

Is It Legal?

Transporting unrestrained dogs in low-sided truck beds has been banned in a handful of states, including California and New Hampshire, and municipalities including Indianapolis, Cheyenne and Miami-Dade. However, in the vast majority of jurisdictions, it's not even illegal to transport children in this manner, so we must rely on common sense and education to protect children and pets alike.

How You Can Help

One can feel terribly helpless witnessing a loose dog in a pickup truck. The best course of action is to try to get the vehicle's license number (if you can do so while remaining safe) and call the local police. Rather than dialing 911, Jill Buckley, ASPCA Senior Director of Government Relations, suggests storing your police precinct's phone number in your cell phone.

Read More: http://www.aspca.org/Blog/cruelty-alert-dogs-in-pickup-trucks