Glässer's disease (GD), also named infectious polyserositis and polyarthritis, is a septicaemia caused by Haemophilus parasuis bacteria which physiologically colonise the nasal cavities. In the events of stress or sudden immunosuppression, these bacteria enter the bloodstream, which leads to severe and significant damage to the thoracic and abdominal cavities, meninges, pericardium and joint capsules.

The most severe outbreak of disease occurs in naïve herds with the highest health status or in purchased breeding animals that are introduced without quarantine to herds with low health status. In a feeder-finisher operation, the disease may occur when piglets originate from more than one breeding sector and each animal is infected with different HPS strain.

Acute and Chronic Disease

Glässer's disease occurs in two forms: acute and chronic. The acute form presents with elevated temperature to 40.5 to 41.5°C, inappetance and vomiting, depression and apathy, lameness due to arthritis and muscle tremors, which often precede death.

In the course of chronic disease, decreased daily weight gains, higher feed consumption per kg bodyweight and higher number of runts with chronic arthritis are observed. The diagnosis is usually based on necropsy of dead individuals and laboratory examinations. The lesions are typical of polyserositis, i.e. thick, viscid or granulomatous exudate, which is found on one or more anatomical structures such as pleura, peritoneum, pericardium, joints and meninges. The only method that allows for confirmation of Glässer's disease is the isolation of Haemophilus parasuis from one or more affected locations.

What are the Costs?

The analyses of Pig World production data from the UK in September 2006 proposed that a one per cent change in mortality was worth £0.50 per pig slaughtered and a 50g per day change in growth rate cost £1.50 at slaughter. All costs associated with mortality and reduced growth rate due to Glässer's disease amount to approximately £3.21 per animal. However, to this sum must be added the costs of reduced feed efficiency and medication as well as additional labour associated with treatment and hospitalization. In total, Glässer's disease could cost the producer up to £5.00 per pig.

Skilled Farm Management

In the context of elimination of Glässer's disease, the key element of herd management is proper organisation of production. In a farrow-to-finish operation, adequate intake of good quality colostrum by piglets that will protect them against Haemophilus parasuis bacteria is essential. Together with slow diminishment of colostral immunity, piglets are colonised with bacteria and they simultaneously develop active immunity.

In order to prevent acute outbreaks of disease, producers should skilfully introduce new gilts into their herds. In addition, it is necessary to control other diseases that have detrimental effects on the system. Instead of eliminating Haemophilus parasuis, the majority of producers prefer to control it with vaccines. According to many veterinarians, this approach may have a beneficial impact on health status of a herd since the lack of contact with microorganism makes animals susceptible to acute outbreak of the disease.

This article was originally published in the Polish magazine, Hoduj z Glowa swinie.

Further Reading Find out more information on Glässers Disease by clicking here.

September 2012