I bought this for my Jack Russell aged 1 year. In less than 5 minutes he had burst it and he had chewed a whole in less than 10 minutes. We were then horrified to find that it contained 3 hard plastic tubes which, once chewed, was very hard sharp plastic that made his mouth bleed. Then as were trying to retrieve the debris we discovered a variety of stainless steel parts that could easily have choked him or necessitated expensive veterinary fees. I would not recommend this to anyone who has an active dog with teeth.