Herpes simplex virus (HSV), varicella-zoster virus (VZV) and pseudorabies virus (PRV) comprise a family of neurotropic viruses known as alphaherpesviruses. PRV is primarily a disease of swine which serve as a reservoir for the virus and the principal source of natural infection for a diverse range of secondary hosts, including cattle, sheep, goats, dogs, cats, and many feral species. Humans and apes are refractory to PRV infection. PRV infects the epithelium of the host where it then spreads to axons of the peripheral nervous system (PNS). The virus opportunistically avails itself of the neuronal retrograde transport pathway which can facilitate transfer to the brain. This unique aspect of PRV allows it to be used as a powerful research tool to study neural connectivity and trace neuronal circuitry in the peripheral (PNS) and central nervous system (CNS).