No one came - Now I'm gone
Spay / neuter your pets, because there are already too many 'unwanted' kittens, puppies, etc.
Rescue / adopt - don't buy.. And if you promise to adopt a pet, do it. Always, always remember this dog, who was supposed to be adopted, apparently, but 'something else came up'..
If your pets do end up having a litter, and you're giving baby pets to new homes, follow up on them. It's easy, especially nowadays when almost everyone has at least a phone camera, there are many ways to share photos and updates online for free, and so on.. Ask to see some photos, every now and then, to make sure that those pets are loved and kept well.
Do everything you can, to prevent any animal ever feeling as sad and unwanted as this poor little dog in the picture.. We can't help him anymore, but we can help other animals.