After a rabid dog bites a person, the dog will die within ten days in most cases. The patient may be in the incubation period may not necessarily die within ten days, but may die if the disease flares up. Rabies is an acute infectious disease contracted by the rabies virus, in which the patient develops a fear of wind, water, and thirst, and in severe cases the patient develops a spasm of the swallowing muscles when he hears the sound of water, which prevents the patient from drinking. The virus enters directly into the mucous membranes and skin wounds through saliva, thus infecting the patient with rabies. There is no cure for rabies, so the mortality rate of rabies is 100%. However, the incubation period of rabies varies, generally 1~3 months. With the occurrence of rabies time and the bite site, the severity of the bite, the amount of rabies virus and so on. Generally the bite in the important parts and the wound is serious, the incubation period can be shortened to a few days; bite the distal extremities and the wound is slight, the incubation period is longer. So when the patient is bitten and scratched by rabid dog, must go to the hospital in time to inject rabies vaccine.