You would have to be doing some extreme pulling to do that type of damage. I tried this collar on myself to make sure it wasn't painful. Any collar can do damage in the wrong hands! But thanks for the comment.
if worried about puncturing the skin ( which has never happened in the 8+ years that i have used them) they sell black hard rubber covers for the prongs.
I can't comfortably say it would fit a dog that large. They do sell extensions, extra hooks for the collars though so if it didn't fit as is, the extensions would be an option to increase the size of the collar
Actually, the most dangerous collar is the choke chain. It crushes their trachea if overused. The pinch/prong collar is safe and a good way to train your dog on a leash. (: