Have you ever really thought about how an airbag can inflate fast enough to stop your head from hitting the dashboard after you hit something?

It's a chemical reaction involving a substance called sodium azide. A sensor in the vehicle senses a collision and sends an electrical impulse to a detonator compound. This compound ignites, and the heat that is produced causes the sodium azide to rapidly decompose into sodium and nitrogen gas. This all takes place in 0.03 seconds, while it takes about twice that time for the passenger's head to hit the inflated bag.

This chemical reaction creates a violent and forceful explosion. This is why we are advised not to place small children in the front seats of cars, as severe or fatal head and neck injuries can occur from the impact of these exploding airbags.

I (Dr. Henri Bianucci) was driving home after a very busy day at the clinic recently. As I crawled along in late-afternoon traffic, observing behaviors such as how many people were texting or talking on the phone, a girl in a small sports car passed by. What struck me was that she had a Lhasa Apso on her lap, between her and the steering wheel, and she was texting.

A steering wheel in today's cars is armed and ready to explode on impact. In an accident, this explosion might save her life, but it likely would have the opposite effect on her furry companion. This would be as true for a dog riding in the passenger seat. As most dogs fall in the size range of small children, they, too, should not ride in the front passenger seat, and certainly not on your lap.

Last year, a 4-year-old bichon frise was presented to our clinic for injuries sustained in a car accident. The car had rolled, and while the human passengers were fine, the dog had a fractured spine. The humans were all wearing seat belts, but the dog was unrestrained. The dog's spinal cord was functionally severed with no chance of recovery. He was euthanized.

Belting your dog in the car might at first sound ridiculous, but vehicle safety harnesses are widely available for dogs and are highly recommended. Your dog is as subject to the laws of physics as you are. We love our dogs like members of the family, and we are devastated when they are injured or killed. We wouldn't dream of allowing our kids or their friends in the car unbelted, so why would we allow our dog?

A safety harness also will prevent a dog from leaping out the window of a moving car and sustaining serious injuries, which we see at our emergency clinic from time to time.

If you are not going to belt your dog, then a pet carrier is recommended. These do not provide the protection of a belt, but they will keep your dog safe after an accident by keeping him out of the road. Also, if you are injured, your unrestrained and protective dog may present a hazard to emergency personnel and impede their ability to help you.

Keep your pet passengers safe. Don't let them ride unrestrained or uncontained, and keep them out of the way of the airbags. If it's wrong for your child, it's wrong for your dog.

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@postandcourier.com.