After being bitten by a dog, it is possible to develop rabies if exposed to the rabies virus. The incubation period of rabies varies widely, from 5 days to 19 years have been reported, usually 1-3 months. Typical rabies manifests itself in three phases: 1. Phase I: the prodromal phase, mainly characterized by low-grade fever, lethargy, headache, general malaise, followed by fear of restlessness, irritability, insomnia, sensitivity to stimuli such as sound, light, wind, etc., and the sensation of tightening of the larynx, and a feeling of itchiness, pain, numbness, and ants walking on the top of the healing wounds, among other strange sensations.2. Phase II: the excitatory phase. Excitement period is characterized by fear of water, manifested as although very thirsty, but do not dare to drink water, see water, hear the sound of water, drink water or just mention the word drink water, will cause severe spasm of the pharyngeal muscles, external sound, light, wind and other stimuli, can also cause spasms of the pharyngeal muscles. 3, the third period: the emergence of paralysis. The patient gradually tends to be quiet, the muscle spasm stops, and then there is respiratory and circulatory failure and death.