Dog bite someone should I be worried about being sued?

My dog the other day bite a boy while my mother was walking him. I am going to go the the house of the boy and speak to the parents and offer to pay for any medical expenses. The dog was not at large i was not there at the time of incident so i don't know why the dog bite it did not growl or show signs of aggression? Should I expect a law suit to come from this?