Locator collar/nametag for pets or tamed animals

My son thought it would be good to have a locator collar for pets because two of his cats may have been underwater when he paddled away in his boat, and he is afraid they may have drowned. If they had a locator collar, he would be able to see on his map if they were still alive. The locator collar or nametag could be made from a nametag to which you add a bit of redstone dust. Pets or mobs to which you attach this nametag will show up on a locator map with either their name or an avatar of their head, and when the chunk that contains the mob is unloaded the mob location is maintained but may not update. It also would be nice to have some way to teleport a pet to you wherever you or the animal are, even if the chunk isn’t loaded. Thank you for your consideration of our idea!