On June 17, 2007, a 1-year-old Chow killed its owner, Phyllis G. Carroll, 63, in Connersville, Indiana. This was the first canine homicide in June; there were four fatal attacks in May, all in one-bite states. Indiana is a statutory strict liability state. (To read more about statutory strict liability, see Legal Rights of Dog Bite Victims in the USA.)
I see many serious injury cases involving Chows. Based upon my experience representing only dog bite victims throughout the USA, the four most dangerous breeds of dog are the pit bull, Rottweiler, Chow and Akita. These breeds also have been designated as potentially dangerous by other organizations and industries. Nevertheless, any dog can turn dangerous, or be friendly, depending on how its owner treats it.
For more on the Chow, read Chow Chow in the great Wikipedia. For more on why dogs bite, see Why Dogs Bite People.