Dr.HOLI pet milk is a HOLISTIC (100% human grade level) product whose processing and material is the same as a human product, so it is made through the special sterilizing process of lactose decomposition. Because a pet has no lactase in the intestine, it can induce diarrhea or gastrointestinal disturbance if pet eats general milk. So pet special milk that the lactose is decomposed is needed.