Ipurchased 2 of these balls for my Chochlate Lab. While not a big chewer she does occassionally gnaw on this toy and I cannot find a tooth mark anywhere. As a further testomonial to this product, I have run over the ball with my riding lawnmower and did nothing more than leave a grass stain on the ball. I would recommend this toy and have to a number of others who have seen them.