Rabies is caused by a rhabdovirus, a minus-sense, single-stranded, non-segmented RNA virus with an enveloped, bullet-shaped virion). The virus infects a wide range of warm-blooded animals, including humans. The virus is widely disseminated within the infected animals, with high levels in saliva. If the animal is captured or killed, examination of its brain for rabies virus can be done in time to determine whether rabies prophylaxis is necessary. The best means to prevent rabies begins with scrupulous wound care, including washing and probing for any foreign bodies (e.g., broken teeth) in the wound. If the animal is not available, or tests positive for rabies, and if the person has not been immunized with rabies vaccine, the treatment of choice is to give human rabies immunoglobulin (HRIg) plus rabies vaccine at separate sites (d). The HRIg should be infused into the wound and the remainder given as a deep IM injection. After onset of symptoms, neither of these should be given. Broad-spectrum antibiotics (a) may be given as part of wound care to prevent bacterial infection, but they will not prevent rabies. Acyclovir (b) and ribavirin (c), regardless of dosage or route of administration, have no role in rabies prophylaxis. Tetanus immune globulin and/or tetanus toxoid vaccine (e) may also be part of the wound care regimen, but are given to prevent tetanus, not rabies.