A ball rolls where you expect it to, and after a while a dog stops finding that interesting. A faceted shape does not. It tips, changes direction and stops dead where a round toy would carry on, which turns a solo game into something a dog has to keep paying attention to. That unpredictability is the difference between a toy that occupies ten minutes and one that occupies about two before being abandoned.

Grooves cut into the surface hold soft food, whether that is paste, wet food or anything else spreadable, and it is the licking rather than the chewing that does the calming work here, since sustained licking is a self-soothing behaviour in dogs. Natural rubber gives it enough weight at 106g to move properly when nudged, enough give to be kind to teeth, and a surface that rinses clean rather than holding onto yesterday's filling.

• Faceted geometric shape that rolls unpredictably
• Durable natural rubber construction
• Grooves hold pastes and soft treats
• Weighs 106g
• Suited to medium chewers
• Rinses clean between fillings

Two things worth knowing. It is rated for medium chewers, and a dog who destroys rubber toys for sport will get through this one, so check it over regularly and retire it once pieces come away. Second, a stuffed toy is a meal as well as a game: take the filling out of the day's food allowance rather than adding it on top, or the enrichment quietly becomes weight gain.

Who it's for: Dogs who need their brains tiring as much as their legs, and owners looking for a calm activity rather than another chase toy.