We bought these for our Great Dane after having a great experience with a chuckit indoor ball but unfortunately these were obliterated in a matter of 30 minutes or so by our dog.  The fuzzy material on the balls became what seemed to be a choking hazard for her as she shredded most of it off within those 30 minutes and began hacking on it (yes, we had taken the ball away by then).  Love their indoor ball but these didn't last long.  It made a giant neon orange mess in our backyard in the process.