Porcine Respiratory Disease Complex (PRDC)

Respiratory disease is a major concern in finishing pigs. It is often a multifactorial syndrome caused by the interactions of several pathogens as well as environmental, management and genetic factors. Severity is dependent on the pathogens involved and housing and management factors.

The term Porcine Respiratory Disease Complex (PRDC) has been used to describe the complex characterized by respiratory symptoms and poor growth in finishing pigs.

PRDC has a multifactorial etiology involving porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine circovirus (PCV) and a variety of bacteria. For this reason pathogens isolated from pigs vary between and within production units.

The variation in pathogens isolated, along with the different time of exposure to the different pathogens, makes control of PRDC difficult and frustrating.

Some of the pathogens involved in PRDC cause specific diseases on their own.
For example:

• PRRSV causes reproductive problems,
• Bordetella bronchiseptica and Pasteurella multocida as the aetiologic agents for Atrophic Rhinitis,
• Haemophilus parasuis causes Glasser’s disease,
• Actinobacillus pleuropneumoniae causes acute or subacute pleuropneumonia,
• Streptococcus suis causes systemic infections.

For information on the individual pathogens involved in PRDC, please follow the links in the left navigation menu.

Control of PRDC
Vaccination plays an important role in the control of PRDC.
Vaccination success is dependent on:

• the passive immune status and age of the pigs,
• the immunogenicity of the vaccine,
• the environment in which the pigs are housed,
• the condition of the pig’s immune system and the potential impact of other pathogens on the pig.

Different farms thus require different vaccination programs.

For details on vaccines available for the control of PRDC please see the Vaccines section.