Dog Cheese Chews are hard-dried cheese chews. The ingredients are yak and/or cow milk, lime juice/citric acid, and a pinch of salt. They are a centuries-old natural chew made from milk, first developed in Nepal by yak herdsmen who were working in the Himalayas and needed an easy way to get a high level of protein for themselves. Dog cheese chews are also known as yak chews or Himalayan chews and are long-lasting dog chews.