Rabies virus exposure grading, divided into three levels, as follows: I. Grade I exposure mainly refers to contact or feeding animals, intact skin is licked, but there is no breakage, the skin can touch the animal or animal secretions and excreta. Second, level II exposure refers to the exposed skin was gently bitten and did not bleed, only minor scratches or abrasions, mainly to determine whether there is a breakage at the exposed skin, if it is difficult to determine the exposure can be wiped with alcohol, such as pain, indicating that there is a breakage of the skin. Third, level III exposure mainly refers to a single or multiple bites or scratches through the skin, mainly refers to the wound has reached the vascular dermis layer, the naked eye can see bleeding or subcutaneous tissue. Grade III exposure can also refer to broken skin that has been licked by a dog or contaminated by animal saliva.