There should be a mandated law for anyone who chooses to breed cats and dogs to sell them, that they must accept them back if the new owner cannot care for them for any reason. Any responsible breeder would do so and ensure their animal does not end up in a shelter.
In addition, there should be more accountability on people who buy animals and not give them the ease of dumping them in a shelter. I'm sorry, but you can't dump your child off when you're tired of them and you certainly shouldn't be able to do so for any living creature. Be responsible and live up to what you said you would do..provide a caring, loving home for the animal for its lifetime.
Jody