Rabies. If you have been bitten by a rabid dog, go immediately to the emergency room as this is extemely dangerous. People bitten have a very high mortality rate unless proper treatment with anti-rabies shots are instituted very early.
2 weeks to 3 months. The incubation period (time from getting the virus to getting first symptoms) is about 2 weeks to 3 months. When the symptoms first appear, it is too late already. Since rabies is fatal, rabies shots should start right away after exposure to the saliva (usually from a bite) of an infected animal.