Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology


Previously, pseudorabies was not considered to be a problem in the midwest but prevalence of the disease has increased over the last five years. In 1974 along, eight isolations of pseudorabies virus were made at the South Dakota Animal Disease Research and Diagnostic Laboratory from outbreaks in the area of northwest Iowa, Nebraska, and South Dakota. As of February1, 1975, here isolations of pseudorabies virus have been made from outbreaks in the area. Iowa State Diagnostic Laboratory reported a six-fold increase in pseudorabies cases in 197 as compared to the preceding four years (5). A survey of swine in Indiana indicated a high susceptibility rate for the disease (18). Because there is no vaccine available for pseudorabies in the U.S. nor is there an effective treatment for the infection, this study was designed to determine the characteristics of the pseudorabies isolates and induce and/or select for a less virulent strain of the virus. Assays were performed to select for a consistent characteristic to serve as a marker for a less virulent pseudorabies strain. They may aid in selection of strains suitable for vaccine development.

Library of Congress Subject Headings

Aujeszky's disease



Number of Pages



South Dakota State University