Complementary food Collagen+ is a chewable snack made from duck gelatine, naturally rich in collagen (50%), a protein highly digestible protein. Wrapped in a delicious layer of meat, it is an excellent alternative to buffalo skin bones. Chewing contributes to the dog's psychophysical well-being, is emotionally satisfying, strengthens the jaw muscles and helps, by mechanical action, to keep the teeth clean. For dogs from 4 months of age.