This is one that I think has developed urban mythical qualities. I've given my dogs rawhide since my first dog when I was a little kid. Everything from the sticks to the bones with the tied ends, to the more modern compressed rawhide bones. Then along comes the internet, and it seems like everyone knows someone who knows someone who heard about someone who's neighbor's dog had to have rawhide surgically removed from their dog's stomach to save it's life since rawhide has the same digestibility as plastic and is as sharp as glass shards. I finally asked my vet, who agreed that she's heard all the stories, but haden't ever had to treat a rawhide case in her career. She said it's more dangerous to let your dog play right after a meal and rick gastric torsion (bloat) than it is to let your dog chew rawhide. My greyhounds chew rawhide (supervised) all the time, and we always get compliments on how white their teeth are... but mention rawhide as the reason, and some dog people totally freek out.