A yak chew is a long-lasting dog treat made from yak and/or cow milk, salt, and lime juice that is hardened by a drying process. Also called Himalayan dog chews, they are a protein-rich, hard, and durable alternative to other chews like rawhide, and are traditionally made in the Himalayan region. They are intended to keep dogs engaged and mentally stimulated through extended chewing, though the hardness can pose a risk for some dogs and should be monitored.