Nova Dog Chews Pork Rolls. Pork Rolls have no artificial colours, grains, additives or flavourings. They are a great treat to help improve your dog s dental health by massaging the gums and reducing plaque build-up as they chew. Always supervise your dog when chewing. Please provide plenty of fresh water along with the chew. Composition 100% Pork Analytical constituents Crude protein 77% Crude oils and fats 16% Crude fibre 0.5% Ash 1.5% Moisture 5%