Significance of the story about Jerry and the dog?

Peter points out that Jerry is emasculated because he has cats instead of dogs.There are many parallels between Jerry's interactions with his landlady's dog and the ones he has with Peter. Jerry invites this comparison when he notes elsewhere in the text that people can use animals to learn how to get along with other people. Taken that way, this passage serves as Jerry's statement of purpose. He wants Peter to "understand" him, and he is willing to use extreme methods to achieve that end.