The use of pseudorabies vaccine in swine is subject to the following restrictions: The vaccine shall be a USDA licensed vaccine or vaccine that is authorized for field trials by federal and State officials. Prior approval for use or possession of the vaccine shall be obtained in writing from the Department. This approval will be granted only for use in swine herds determined to be infected or threatened with infection by pseudorabies. At the time of vaccination, all swine shall be individually identified by a method approved by the Secretary.