Natural chews get sold on what they are made from and bought on how long they last. Hardly anybody turns the tub round to look at the fat figure, and on a chew that is the number that decides whether it is an occasional thing or an everyday thing.

There is nothing to argue with in the ingredient list here, because it is four characters long: 100% lamb. NAW add nothing to it, and state their lamb range is gluten and grain free. The analysis is where it gets interesting — protein a minimum of 45.43% and fat 40.53%, which are close to level, with moisture 5.8% and ash 7.74%. Drying a lamb tail concentrates what a lamb tail already is, and a tail is a fatty cut. NAW describe the chewing as helping break down plaque, and the occupation as enrichment; it is cleared for dogs over 4 months of age.

• 100% lamb, with no additives declared
• Protein a minimum of 45.43%, fat 40.53%
• Moisture 5.8%, ash 7.74%
• Gluten free and grain free
• Suitable for dogs over 4 months of age
• Sold in a 1kg tub and in a smaller pack

The fat is 40.53%, and that is the fact to take away. Protein and fat run nearly level, which makes this a rich chew rather than a lean one — fuel for a lean, working, hungry dog, and a conversation with your vet for a dog carrying weight, a dog on a fat-restricted diet or one with a history of pancreatitis. NAW supply no piece count, no piece size, no calorie figure and no suggested number per week for the 1kg tub, so how often it comes out is a judgement you are making with no help from the label. It is also a chew rather than a toy, which means somebody stays in the room.

Who it's for: owners of a lean, busy dog who needs a real job to do for twenty minutes, and anyone reading ingredient lists closely enough that a single-ingredient chew is the point rather than the marketing.