A veterinarian was feeling ill and went to see her doctor. The doctor asked her all the usual questions, about symptoms, how long had they been occurring, etc., when she interrupted him: "Hey look, I'm a vet. I don't need to ask my patients these kind of questions: I can tell what's wrong just by looking. Why can't you?"
The doctor nodded, looked her up and down, wrote out a prescription, and handed it to her and said, "There you are. Of course, if that doesn't work, we'll have to have you put down."
