Unfortunately, there are far too many people out there who don't care for their pets properly, treat them badly, or neglect them while they have them, and then think its fine to just dump them when they tire of them. The really sad part of this is that, as long as the punishment for animal neglect or cruelty continues to be just a smack on the wrist, such as a fine, or being told that they can no longer own any animals, things are never going to get any better. If they were to pass some federal laws, which makes the punishment more fitting for the crime, such as jail time for people like this, people would think twice about doing it!
Myself, I think that anyone that neglects, willfully hurts, or kills an animal, especially an animal that is a pet who is in their care, should be locked up and have the same thing done to them! Then the punishment would REALLY fit the crime. They wouldn't think that is was acceptable to treat an animal that way, if someone gave them a dose of their own medicine! Unfortunately, that will never happen, but making it mandatory to do jail time for animal cruelty or neglect would be a good place to start.
People who do things like that to a helpless animal, especially an animal who probably loves them, make me sick!