Some questions about the ten days observation:
The (third report) had wroted to in 1960:
start vaccine at first signs of rabies in the biting animal,start vaccine immediately；stop treatment if animal is normal on the fifth day after exposure.
The (second report) had wroted to in 2013:
Administer vaccine immediately.stop treatment if animal remains healthy throughout an observation period of 10 days or if animal is killed humanely and found to be negative for rabies by appropriate laboratory techniques.
(1)What is the reason for the observation of 5 days to become the ten days observation? Was there a case that breaks the five days observation?
(2) The word "healthy" in the ten days observation refers that the animal is health or alive in tenth day？If it means health, how to judge? Because animals often die from disease to death need more than one day.