I wanted to know how can I remove a dog from a world. I accidentally spawned 2 dogs and I only need 1 of them, but I don't know how can I remove it. Thanks in advance.

If you use some collar shears on the dog this will make it a wild dog (no owner) after 3 seconds you can click on them again with the collar shears this will turn the dog into a wolf, you can then kill the wolf by any means you would like.