I am a veterinarian and so I deal with these situations often. The 10 day quarantine has to do with the fact that not every animal with rabies is capable of passing it along. The virus has to have made it to the salivary glands to be passed to something/someone bitten. We also know that if rabies is far enough along to be transmissible (in the salivary glands) then an animal will either be showing signs of rabies or be dead within 10 days. As a result the 10 day quarantine exists. If the animal is not dead or showing signs of rabies after 10 days, then it is not possible to have passed it along even if it is infected with rabies, so the bite victim can be considered safe (though prophylactic shots have likely already been started). At this point the animal, if a dog or cat, is either vaccinated or has to undergo a yet longer quarantine depending on its current vaccine statues. Dogs that were vacci ated before but just out of date can often be updated on vaccines and go on their merry way. Dogs never vaccinated before often times have to undergo quarantine of up to 6 months.