LORELAI: I freaked out. I’m so sorry. I never meant to treat you like that; I’m not very good at this, ask Skippy.
When she apologises to Max for the awful way she treated him, she mentions Skippy the hamster, that she abandoned rather than care for. Skippy was also treated appallingly, and Lorelai recognises that the hamster is symbolic of the way that she tends to dump people rather than deal with any problems in the relationship.