In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Q: Sentence1: Jacob noticed his dog was whining. Sentence2: Jacob investigated and found his dog's leg hurt. Sentence3: He took the dog to see the vet. Sentence4: The vet made a cast to set the hurt leg. Sentence5: Within a few weeks, Jacob and his dog were playing again!
A:
Jacob, Vet, Dog