The euthanasia problem is a sad commentary on our society. Simply put, there are just too many people who should not be pet owners because they are ignorant, uncaring, ego-centered or just plain unworthy to care for a pet.
We've all driven in the pouring rain and seen two dogs on a short leash chained to a tree. The owners will tell you that these are "outdoor" dogs, not "indoor" dogs. How many people go on a three-week vacation and leave their three dogs outside to bark 24-7 in the blazing sun? It is OK because a neighborhood child will come by once a day to feed them?
People who cannot take care of animals should just admit it, get over it and leave the caring to people who can be responsible pet owners. Maybe a law needs to be passed to ban ignorant humans from owning animals. That should take care of the problem.