I have found pets let loose in the woods. A 50% chance of euthanasia, with decent food and care, is a much better outcome. However, personally, I seek out no-kill shelters and support them. The Humane Society deals in sheer numbers and has lawyers, and so has specific guidelines for when to put an animal down that might still make a good pet. In addition, those animals that do manage to survive in the wild can quickly become an ecological or health disaster. They prey on other animals and they can spread diseases such as rabies.