Incubation period varies for rabies. So if the vaccine starts producing antibodies before virus reaching brain, vaccine is effective. You are within the incubation period of the disease. so the vaccine can be effective. If possible please get immunoglobulin too. Behaviour of rabid dog/cat is:- -- Any change in its normal behaviour suggesting either undue aggression or depression. --- Running aimlessly and attacking others without any provocation. --- Becomes too drowsy and withdraws itself to a corner. --- Excessive salivation. --- Change in its voice/bark. --- Refusal to feed or eating unusual objects like stone, paper, wood, metal pieces, etc. --- Death of the animal.