The dog’s saliva enters the mouth, and if it suffers from diseases such as mouth ulcers, it may cause the rabies virus to spread through the bloodstream, leading to human infection with the rabies virus. 1. Dogs do not carry rabies virus: If dogs do not carry rabies virus in their bodies, they will not spread rabies through saliva. 2. The dog carries rabies virus: If the dog carries the virus in its body, it means that the saliva also contains the virus, which enters the human mouth, and in general will not spread rabies, because rabies is not spread through the digestive tract. However, if the patient suffers from diseases such as mouth ulcers, it may cause the rabies virus to spread through the blood, leading to human infection of rabies. In addition, rabies is a serious disease and once infected, the lethality rate is very high, so it is important for patients to be actively vaccinated against rabies to protect themselves in the event of a possible rabies exposure.