One day a lady took a dingo to the vet

One day a lady took a dingo to the vet. the doctor looked at the dingo and shook his head. "i'm sorry your dingo is dead" said the doctor. "how could you be so sure" the lady said. so the man left the room and come back with a labrodore retriever. it stood up on its hind legs and sniffed the dingo and shook its head. the doctor left the room again and come back with a cat. the cat also sniffed the dingo and shook its head. the doctor said that the dingo was 100% dead. with the lady still in shock, the doctor handed the bill to the lady. "$400, why $400?". the doctor replied "if you had've believed me first it would of been $60". "but why still" the lady insists. to which the doctor says "because you had a lab report and a cat scan!"