Pseudorabies virus/Aujeszky’s disease

Pseudorabies virus (PRV/Aujeszky’s disease) is caused by a type 1 porcine herpesvirus. Infections with the highest mortality rate are those affecting suckling pigs born to a susceptible sow. Baby pigs in the fatal course of the disease exhibit difficulty breathing, fever, hypersalivation, anorexia, vomiting, diarrhea, trembling and depression.

Within this age group, the final stages of infection are commonly characterized by ataxia, nystagmus, running fits, intermittent convulsions, coma and death. Death usually occurs 24–48 hours following apparent clinical symptoms. The clinical events of the disease in weaning and fattening pigs are essentially the same except the course of the disease is usually protracted 4–8 days.

The mortality rate in mature pigs may reach 2%; losses, however, do not usually occur. While the clinical course in pregnant swine is virtually the same as in mature pigs, there is variation due to transplacental infection of fetuses. Transplacental infection with PRV can occur, and depending upon the stage of gestation, one of the following sequelae may occur: resorption, premature expulsion, birth of macerated fetuses, stillbirth, or birth of weak, infected pigs.

An assessment of the exposure to pseudorabies virus via natural infection or vaccine is facilitated by a measurement of antibody in the serum.