The document summarizes the characters in the story "A Triumph of Surgery" by James Herriot. There are three main characters: 1) Mrs. Pumphrey, a rich lady who owns a dog named Tricki that she overly pampers, 2) Tricki, her dachshund dog that becomes ill due to overfeeding, and 3) Dr. James Herriot, the veterinarian who treats Tricki and helps him recover through proper diet and exercise rather than surgery.