It is well documented by Dr. David Mech who studied wolves for decades.  

Barbara



  Actually, I argued this on another list but apparently it is not the case. 
  Wolves and wild dogs leave the stomach behind when they eat a carcass and
  this is apparently well documented, but where I don't know.  Kay on the
  silverpets list has all the info on this.  I think dogs would naturally eat
  raw meat, but may occasionally eat vegetable matter for whatever reason, but
  I don't think it would be their food of choice.  However, people will never
  agree on this subject so its best left alone I think.  Dee