Trauma is the leading cause of death for both Chihuahua puppies and dogs. This includes terrible accidents such as dropping or stepping on the Chi. However, it also includes trauma from car accidents, both being hit and being injured as a passenger.
Every day there are 27,000 vehicle accidents and there is a fatality every 15 minutes; This is just in the U.S. alone. If a puppy or dog is not buckled in, he will be thrown, often with enough force to cause broken bones, internal injury and even death.
So, making sure that your Chihuahua is safe while in the car is paramount. In addition, the right car seat can dramatically reduce motion sickness while traveling. For this breed, booster seats are the way to go.