We own two English Mastiffs. "Moose" is a big boy weighing in at 223 and is a POWERFUL chewer. "Lilly" is petite at a dainty 137 but has chewed her way through untold toys, furniture, deck chairs etc. We bought two Hurleys at Christmas, handed them over to the team and waited to see what happened. Thus far, both Hurleys are intact and still going strong. I will definitely continue to buy replacement Hurleys if/when needed.