Boxer dog loves them
My first unit was a gift for my Boxer. She went wild over it but it quit functioning due to electronic problems within an hour of use. I have purchased five more from PutinOnTheDogShop.com and have had no further problems. The batteries do not last that long and must be replaced often. I put all five out for my dog to play with allowing me to replace batteries at my convenience. A friend told me that her bulldogs destroy the outer covering rather quickly. Have not had that problem as my pup does not tear up her toys. I would suggest you to purchase more than one.