Why does Mrs Pumphrey think the dog’s recovery is “a triumph of surgery”?

Explanation

Mrs Pumphrey thought that the dog’s recovery was “a triumph of surgery” because in two weeks, Tricki had recovered completely and had been transformed into a hard-muscled animal. When Tricki saw her,it leaped into her lap and licked her face. She was so excited that tears started rolling out of her eyes. She declared Tricki’s recovery as a triumph of surgery to express her happiness and gratitude towards the doctor.