I have pembroke corgis. I gave the medium ball a try but it was too big because they couldn't open it for the treat. I like the loop on the top that they added and the velcro seems like it will last longer than the ones I bought a couple years ago. They are made so strong that when the velcro wears out, it's just better to buy a new ball then try and sew new velcro on. My two corgis love the play time when they see the balls. Will continue buying when these wear out.