Complementary Feed For Dogs Our canned food Belcando® Single Protein is available in six selected meat varieties. Single Protein cans can also be used in combination with the food supplement Belcando® Mix it GF for diagnosis (elimination diet) and sustained feeding for food intolerances. Also ideal as a source of protein in elimination diets. Single Protein can be used for long term feeding for food intolerances - again in combination with Mix it GF.