By the University of Minnesota Swine Group
The reporting on April 30, 2026 of pigs positive to pseudorabies in Iowa and Texas is a good reminder that we cannot be complacent when it comes to infectious diseases.
Pseudorabies virus (PRV) causes a devastating clinical picture resembling rabies in young pigs, thus the name. This disease, also known as Aujeszky’s disease, is most severe in piglets, causing high mortality as well as tremors, seizures, paralysis, incoordination and “dog-sitting” signs. As they get older, infected pigs experience respiratory disease with fever, coughing, and pneumonia. In sows, PRV causes abortions and stillbirths and in boars the virus can be shed in semen. PRV transmits primarily by direct contact with secretions of infected pigs but other routes such as exposure to contaminated fomites or aerosols can lead to infection.
PRV was eradicated from U.S commercial swine in 2004, but it remains prevalent in feral pigs mostly in the southern states. PRV can affect other mammals and notably will kill dogs and cats if they get infected by eating PRV positive carcasses. Finding dead cats or dogs can be the first sign that the virus is present in the farm.
To keep farms PRV-negative, producers should only bring replacement animals and semen from PRV negative sources, ensure that pigs do not come in contact with feral pigs, and should enforce biosecurity protocols of visitors and employees by using farm dedicated clothing and footwear exclusively, and avoid sharing equipment or materials with other farms.
Veterinary diagnostic laboratories are well equipped to diagnose PRV via PCR or ELISA tests. PRV does not pose a risk to consumer health or affect the safety of the commercial pork supply. USDA APHIS is currently investigating the current case and asking producers and veterinarians to stay vigilant. For any questions, contact your veterinarian.