Why didn't Slinky Dog jealous of Andy's dog, Buster from Toy Story?

Woody was jealous of Buzz because he was Andy's favorite toy and Buzz became Andy's new favorite toy. When Andy received a puppy named Buster for Christmas end at Toy Story but Buster was first appeared in Toy Story 2. Slinky Dog wasn't jealous of Buster that he should be jealous because Buster was a real dog in life that Slinky Dog wasn't a real dog just a toy.