'The dog that fetches will carry.'-i.e. A talebearer will tell tales of you, as well as to you.
[1830 R. Forby Vocabulary of East Anglia 429]So Nellie twisted what you said and told it to Miss Wilder. ‥'A dog that will fetch a bone, will carry a bone.'
[1941 L. I. Wilder Little Town on Prairie xv.]All this gossip reminded Shirley‥of the saw The dog who brings a bone also will carry one away.