A condition in which the skin or cartilage becomes dry and crusty. Crusty skin of the ears, head and/or neck. A crusty skin can be a cause of concern. Sometimes the skin of your pet crust because it is playing on the ground and picking up debris, which can adhere to its body. Crusting of the skin can also be caused by an infection. In this case it is advised to consult a veterinarian to determine the cause and choose a treatment.