NVAP Reference Guide: Pseudorabies (Control and Eradication)

Last Modified: March 20, 2024



Control and Eradication


Aquatic Animal

Animal Health Emergency Management

Animal Movement

Animal Identification 


Pseudorabies is a contagious, infectious, and communicable viral disease of livestock. The pig is the only natural host. However, pseudorabies virus (PRV) can infect most mammals, to include, cattle, goats, sheep, dogs, cats, and wild animals such as opossums, raccoons, rodents, and skunks, except humans, horses and birds. 

Transmission of PRV can occur by direct nose-to-nose contact or venereally, including insemination with infected semen or transplacental transmission. Indirect transmission can occur by inhalation of aerosolized virus or ingestion of contaminated water.  

PRV is still found in feral swine populations.  All feral swine should be considered a potential risk for PRV and other diseases of swine. The PRV virus commonly found in feral swine primarily transmits through sexual contact. That said, other transmission methods as described above are possible.  Biosecurity to prevent feral swine exposure is important to protect swine.  

In general, the virus infects the central nervous system (CNS) and the respiratory tract. Clinical signs observed depend on the age at time of infection. Young swine are very susceptible and can develop severe CNS symptoms. Mortality can reach 100 percent in piglets. Clinical signs in weaned pigs, depends on age. Few weaned pigs develop a fatal CNS disease but more often will develop a respiratory disease.  

Grower finishing swine typically develop only a respiratory disease component. Adult swine may have a respiratory disease component and if pregnant, depending on the trimester of pregnancy, may abort, have stillborns or give birth to weak piglets.  

Pigs of all ages display a generalized febrile response, anorexia, and weight loss. Infected pigs remain latently infected following clinical recovery.  

PRV Program

Through State-Federal- Industry efforts, PRV was eradicated from the commercial industry in 2004. The U.S. commercial industry has remained free. Learn more about swine programs including the PRV program.

Interstate Shipment

If you are testing for interstate shipment, contact the State animal health official in the destination State for specific requirements.

International Export

When preparing to test and certify an animal for international export, become familiar with the requirements by visiting the National Center for Import and Export, Animal Regulations Library.

You should also contact the APHIS –VS Area Offices to confirm the current requirements for the destination country and to get additional guidance. 

As an alternative, you may have the exporter or broker contact the ministry of agriculture of the importing country for specific regulations and the need for any permits.