Glässers Disease is caused by the bacterium Haemophilus parasuis (Hps), of which there are at least fifteen different types. It is found throughout the world and organisms are present even in high health herds. If such herds are set up using SPF or MEW techniques and are free from Hps it can be devastating when they first become contaminated, producing an anthrax-like disease with high mortality in sows.
In the majority of herds in which the bacterium is endemic, sows produce a strong maternal immunity which normally persists in their offspring until 8 to 12 weeks of age. As a result, the effects of the infection in weaners are usually nil or minimal. . Disease may however be seen in sucking pigs. Pigs usually become sub-clinically infected when still protected by maternal antibody and then stimulate their own immune response. If however the maternal immunity wears off before they become infected they may develop severe disease. This is usually sometime after weaning. It can also act as a secondary pathogen to other major diseases particularly enzootic pneumonia (EP) (Mycoplasma hyopneumoniae). Outbreaks of disease are sometimes experienced in sucking pigs, particularly in gilt herds.
Hps attacks the smooth surfaces of the joints, coverings of the intestine, lungs, heart and brain causing pneumonia, heart sac infection, peritonitis and pleurisy. It is respiratory spread.
Symptoms
Sows
- Disease is rare in sows, unless the dry sow is naive.
Occasionally seen in gilts:
- Lameness / stiffness.
- Slight swellings over the joints and tendons.
- Meningitis rarely.
Piglets
Acute disease:
- Rapidly depressed.
- Elevated temperature.
- Inappetence .
- Reluctant to rise.
- Characteristic feature a short cough of 2-3 episodes.
- Sudden death in good sucking piglets is not uncommon.
- Also causes individual cases of arthritis and lameness with fever and inappetence.
Chronic disease:
- Pale and poor growing pigs.
- Sudden deaths may occur.
Weaners & Growers
- Pigs with gl?ssers disease become rapidly depressed or may be just found dead.
- Elevated temperature.
- Stop eating.
- Reluctant to rise.
- Fever.
- Nervous signs – fits and convulsions including meningitis.
- Poor pigs, wasting, hairy often result.
In young growing pigs the following are common:
- Fever.
- Mild meningitis.
- Arthritis.
- Lameness.
- Pneumonia.
- Heart sac infection.
- Peritonitis and pleurisy.
- A characteristic feature is a short cough of only 2-3 episodes.
Causes
- It is respiratory spread. Disease may be precipitated by PRRS, flu or EP.
- Poor environments, draughts etc. predispose.
- Stress.
Diagnosis
This is made by clinical observations, post-mortem examinations and isolation of the organism in the laboratory. Glässers disease has to be differentiated from Actinobacillus suis infection, App, mulberry heart disease, streptococcal meningitis and arthritis and bacterial septicaemias.