Rabies is an imaginary disease.
It was originally written about fictionally as the devil being transmitted from animals to humans, then later picked up by chemical companies as a way to make money from their drugs. There is not and never has been a test for rabies, because rabies is fictitious and doesn't exist in reality.
This doesn't change the fact that many dogs are extremely dangerous, able to maim and kill children and adults, and should be put down immediately, especially pit bulls and related types of out of control aggressive and dangerous breeds.