So a lady brings her pet duck to the vet. She tells the doctor, "hello, I am pretty sure that my duck is dead, but I would like you to take a look at him and make sure." The doctor says he will, takes out his stethoscope and puts it on various places on the duck. He says, "I'm sorry ma'am, your duck appears to be dead."

She asks, "Is there just one more test you can do to be absolutely sure?" The doctor again agrees and goes and summons his dog. The Labrador Retriever comes into the office, looks at the duck, gives it a sniff, looks at the doctor with sad eyes and gives one single bark before he leaves the room.

The doctor then brings the office cat into the room. The cat looks at the duck, smells the duck, looks at the doctor with sad eyes and gives one single meow before leaving the room.

The doctor says, "I'm sorry ma'am, but this duck is dead, and I'm 100% sure at this point. Let me write you up a bill." The doctor hands the bill to the woman and she says, "But how can this have cost me $150?" The doctor replies, "Well it was $100 for the Lab test and another $50 for the CAT scan."