Aujeszky’s Disease   Pseudorabies


Other names

Pseudorabies.  PRV. ADV.  Suid herpesvirus (SHVI).  Aujesky’s Disease

Causal agent

Virus.  Herpes DNA virus.  Enveloped

Age group


All age groups

The disease is notifiable and a class B disease OIE.  Several countries are free of Aujesky’s Disease.

Clinical signs

Naive herds


Neonatal pigs

Present with a range of severe central nervous signs from fitting to severe Incoordination.  The piglets may present as sitting like a dog due to posterior paralysis.  Mortality is high

Weaned pigs

Central nervous signs may be reduced and an increase in respiratory signs

Respiratory diseases often associated with secondary infections

Animals can waste and suffer ill thrift and are often stunted

Growing pigs

The CNS signs reduce and the respiratory signs increase.  The degree of respiratory disease depends on secondary infections


Reproductive signs predominate. Sows may abort and animals infected close to term give birth to stillborn or weak piglets

On established herds

May be few clinical signs

In other species

The pig is the natural host for Pseudorabies

In other animals the disease either causes no problems or is invariably fatal

In cats, rats and mice the disease kills rapidly and this can be important in diagnosis

Dogs present with a rabid signs, hence Pseudorabies

Cattle and sheep and rarely horses present with a mad-itch

Pseudorabies does not affect man

Dead finishing pigs from an acute Pseudorabies outbreak

Weaned pig showing signs of severe depression.  The animal also presented with pneumonia and head pressing



Transmission within a herd is nose to nose, through mating both natural and AI and transplacental

The virus can survive short periods in the air, up to 7 hours with the RH higher than 55%

The virus is rapidly inactivated when exposed to drying

Infection of wild animals also help to spread the disease

The disease can spread up to 2 km by air under the correct conditions

Transmission can occur between trucks in transport and tailgating of trucks should be avoided.  Also parking next to other pig trucks at service stations

Incubation period

2 to 4 days


Post-mortem Lesions


Gross lesions are often absent or minimal

A serous to fibrinous rhinitis is common and a necrotic tonsillitis.  This does require detailed examination of the head

Respiratory lesions of complicated pneumonia often present

The liver and spleen typically have yellow-white necrotic foci (2-3 mm)

A necrotic placentitis and endometritis may be observed.  In aborted piglets there may be necrotic lesions in the lungs, liver, spleen and tonsils

Post-mortem findings

Normal tonsils at the back of the pigs mouth

Necrotic debris in the nasal passageways and tonsils in a pig with Pseudorabies



Clinical signs and virus isolation

Serology is of limited use in acute cases as it can take 7-10 days to produce antibodies

Diagnosis confused by maternal antibodies which may persist for up to 4 months

Differential serology may be used to differentiate vaccinated from field infected pigs





Vaccination.  Use of a variety of modified live vaccines have been developed. The vaccine reduces shedding and latency, but does not remove it.

Vaccines have been made from genetically modified virus.  These viruses have a variety of nonessential proteins missing from their genome

In Northern Ireland, the vaccine uses a g1 deleted vaccine strain.  In other countries gIII, gX and gp63 have been used.  It is important not to mix vaccine strains as they can recombine.  The gX vaccine helped eliminate the disease in the USA.


Good biosecurity.  Purchase only from Pseudorabies Free Herds.


Vaccination and elimination leads to Pseudorabies disease free farms and areas

Depopulation followed by 30 day no pigs is recommended

Countrywide eradication programmes are successful but very expensive.

Common differentials


Streptococcal diseases can produce similar necrotic lesions in the liver and spleen.  Other causes of neurological, respiratory and reproductive diseases.