Pseudorabies (Aujeszky's disease, "mad itch", infectious bulbar paralysis) has been present in the United States since 1813. 1 In 1902, Aladar Aujeszky in Hungary determined that the disease was of non-bacterial origin. 2 Aujeszky investigated two fatal cases of pseudorabies (PR), one affecting a bull and another a dog, and differentiated this syndrome from rabies.3.4·5 Although PR is most prevalent in swine in the United States, it is a devastating disease in cattle, sheep, goats, dogs and cats. Infection in highly susceptible domestic animals results in rapid death, but these dead-end hosts contribute little to the spread of PRo Adult swine are more resistant to pseudorabies virus (PR V) infection and can develop latent infections, serving as natural reservoirs for the virus. This condition allows for the survival and spread of the virus not only to swine but to other domestic animals as well.