We have a German Sheppard and a Border Collie mix. Between the Sheppard's strong jaw and the Collie's need to shred toys, we've been through a ton of Frisbees. We've had these over a month now and, other than a few teeth impressions, they look brand new.
I have a german shepherd dog (3 yrs old) who loves to play in the pool with her toys. In the past she has shredded many toys in the pool leaving string pieces everywhere. We bought 2 of these and she loves them. Even though she has put many teeth holes in them they are still holding strong. When these wear out we will definately buy more of the same.
I LOVE the Dura Foam Disc...My shepherd loves it, she is a very high drive dog with a nervous mouth. She can bite into it without damaging her teeth. We play tug of war with it and it never damages the disc. I started using it as a water dish when out and about and it works very well! I HIGHLY recommend it!