We love our dogs and just like humans, they go through changes and developments throughout their life. Dogs who are otherwise on their best behavior can suddenly display signs of bad behavior. Considering that pets have no sense of morality, they do not do something since it's "incorrect" or "right." They simply do whatever works.
When most people think of rabies, they picture a violent animal that is foaming at the mouth. No one would like to see their beloved pet in this state. The fear of rabies is very real for many pet owners. People often forget that wildlife, whether it is small, cute, and quit can be dangerous.