A complementary pet food for adult cats. Encore Mackerel Fillet Loin is 100% natural and made with only one ingredient- Mackerel Fillet. Each mackerel fillet provides a natural source of Omega 3 and taurine and unlike many other treats they have no added sugars. There are no artificial flavours, preservatives or colours used in our treats, so your cat will find them delicious, naturally.