I remember seeing something posted here about dog adoption. It was something written from a dog's perspective, countering the argument that adopting a new dog was trying to replace the old one. I think it pointed out that the new dog was in need of a home just like the old one was. I tried searching for it but I couldn't find it. Trying to convince someone who is grieving the loss of their old shelter dog that getting a new dog is not being disloyal to their old dog.
Rescuing/adopting an animal that needs a loving home is a wonderful feeling! I encourage people to give it a try.