Where do people find this crap. MYTH, MYTH, MYTH. Why is it that myth is more important to people than fact? Why is it so hard to believe that a young man who practiced his guitar for 6 months to a year, could improve enough to impress older players. It actually happens quite often. I have seen plenty of young players who couldn't put two notes together suddenly bloom and become outstanding. No deals with the devil, just hard practice. If you would like to read a through rebuttal of this devil nonsense then read this post HERE.
Okay, so after he sold his soul to the devil years later he dies. Of course he wasn't attacked by dogs, and he didn't say he was attacked by dogs. He was poisoned while playing in a juke joint. According to either Son House or Sonny Boy Williamson,( I thought it was house, but I have seen Sonny Boy mentioned as well) Robert was offered an open flask of whiskey. Son knocked the bottle out of his hand and told Robert to never drink whiskey from an opened flask. Robert was angry, and when another opened flask came by he drank from it. It was poisoned by the husband of one of Robert's women friends. The poison didn't kill him instantly, he lingered for several days. Long enough for his mother to reach him before he died. He wasn't crawling on the floor baying at the moon, or anything else. He was far too sick. The poison didn't kill him, but accumulated fluids filled his lungs and he died of Pneumonia. He did renounce his music from his death bed according to his mother, but given the circumstances, and his young age, it is understandable that he would feel that way. this clip here is another wild interpretation of the death of Robert Johnson.
Finally here is a clip that gets pretty close. To what really happened. However, Robert did not die alone, but no supernational event caused his death. Then the interesting epilogue as told by Son House tries to figure out why Robert was so good at guitar. He still makes the devil claim, but then makes other claims, and finally accepts the fact that people believe otherwise! Very clever.