Page 322 of articles about health

The factors of virulence allow the pathogenic strains to survive inside the animal and cause the infection, while the non-virulent strains lack these factors and can only survive in the upper respiratory tract as colonisers.

Pig rearing practices in the country need a lot of improvement considering that about 70% of pigs are on a backyard level.

On a conventional farm with no problems with Glässer’s disease, it is possible to isolate various strains of Haemophilus parasuis which colonise piglets while being in balance with the animal’s immunity without producing pathology.

Experimentally it is difficult to demonstrate whether a pathogen can be windborne and if so how far.

H. parasuis is a gram-negative bacillus of small size, which belongs to the Pasteurellaceae family. The group characterized by fibrinous polyserositis and fibrinous arthritis became known as Glässer’s disease.

We may have some highly efficient vaccines, but we shouldn’t forget that for their application we must obtain good diagnostic information, and that in all cases we should not lose sight of good management and a good control of the concomitant diseases.

The usual pig viruses are H1N1, H3N2 and H1N2. The original H1N1 pig viruses have been largely replaced by poultry viruses in pigs. The H3N2 viruses were from humans originally. The H1N2 viruses are re-assortants from human viruses (H and N genes) and poultry viruses.

Between 1995 and 1997, at the beginning of an epizootic called “maladie de l’amagrissement du porcelet” (MAP), it was observed that the farms that were most affected and that had the most losses, generally presented obvious deviations from what we would consider to be a suitable management of the animals and facilities. This is why Dr. François Madec made a list of management practices with the aim of improving the anomalous situation observed.