No, much to the dismay of our many community members who request this, we have no intention of returning old pets and items to Adopt Me. Once these items have left the game permanently the only way to obtain them is through trading. 

We understand that this answer is disappointing as many of our beloved creatures are now extremely valuable and hard to trade for, but we feel that this is rewarding for our older players and gives our newer players something to aim for as well as a way to positively engage with the community.

There are, however, some pets that leave and return. These are the Weather/Seasonal pets, and you can find more about these pets and the weatherboard here.