Read a few blogs and posts and you begin to see a trend - tripe is a superfood.
The untreated stomach lining (it has to be untreated as the processing and bleaching runs a lot of the good stuff for dogs down the drains) is full of protein, pro-biotics (so think Yakult for dogs), vitamins and minerals.
I was reading however that a stomach fed on a diet of grass is different to a diet fed on grain. Because the tripe isn't treated or processed , a grain fed stomach might still contain grain in the inner recesses of the stomach so if your dog is sensitive this is something to keep in mind.
Henley Raw however contains free-roaming grass-fed lamb so suitable to all dog walks of life.
Composition: 70% Lamb Tripe, 10% Duck, 10% Duck Bone, 5% Lamb Liver, 5% Other Lamb Offal
Typical Nutritional Analysis: Fat 8.06%, Moisture 74.9%, Ash 2.1%, Fibre 0.2%, Protein 14.9%