Cons:
* It should be apparent as an ice filled with goodies, freezable and ausschleckbar, but despite the huge size of the Kongs (XL for our shepherd), the opening is quite small to lock out. I fear that one of the Kong afterwards must, rinse very good, so in there scruffy nothing!
* You should not use to throw, because prey games generally are not good for dogs (adrenaline / stress-distributing)