Pseudorabies (PR) is receiving more attention today than ever before. Why is this? Historically, PR can be traced back to the mid 1800's in the United States. Although sporadic outbreaks were reported prior to 1975, it was not until the late 70's and 80's that the importance of PR was appreciated. This can possibly be explained by an increasing incidence of clinical disease outbreaks, and economic losses associated with those outbreaks. Three reasons have been suggested for the increase in recent outbreaks!: (1) there has been a change in swine management towards intensification of producand confinement (2) there has been a successful eradication of Hog Cholera, and since it and PR can have similar clinical signs, more PR is being recognized (3) there has been an increase in awareness of PR as a disease entity.