The Country Doctor: Frank Kafka

This was an odd short story that I couldn't find a simple explanation for. A doctor is summoned to a home of a sick boy 10 miles away. His horse died the night before and as he walks to the stable is unsure what to do. Just then a man comes out of the stable with two beastly horses. He puts the doctor in the carriage and claims his payment will be the servant girl, and then slaps the horses so they take off. The doctor can't control the horses and leaves knowing Rosa, the servant, is going to be raped. He arrives to the home in record time and finds a healthy boy who asks the doctor to just let him die. After some weirdness where people make him strip and lay down with the patient he sees the boy has a huge gaping wound with worms coming out of it. He leaves knowing the boy will die and it takes for seemingly ever for him to get home. The book seems to be describing a dream the doctor had, or is having. There seems to be these ideas that the Doctor wants to “have” his servant Rosa, and maybe there is a fear of not knowing what is wrong with a patient, hence the gnarly wound.