Page 38 of articles about health in Articles

Skin disease is one of the most difficult areas to assess clinically and on gross pathology.

Basic preventative measures of management should be included in the control of the disease, such as adequate temperature control of the barns, a complete all-in all-out hygiene and disinfection, and the avoidance of any mixing of animals from distinct sanitary origins.

The performance and conformation of the pig (the phenotype) depend on the combined effects of its genetic make-up (the genotype), which is mostly fixed at conception, and the environment, which includes health, nutrition, management, housing and climate.

Since 1987, Porcine Reproductive and Respiratory Syndrome virus (PRRS) has become a global drain on pig productivity, profitability, and many a producers’ morale. One thing that remains certain is PRRS virus continually finds ways to circumvent our best bio-management efforts. PRRS marches on in a ceaseless continuum of antigenic change making current vaccines and other control techniques of limited value.

The decrease in the contact time between the mother and her piglets, due to the common practice of early weaning, has led to the appearance of some piglets that are not completely colonised or that have not acquired a sufficient level of maternal antibodies. On mixing with other litters, these piglets are faced with distinct strains while lacking the necessary antibodies against the disease.

In the diagnosis of nervous conditions it is difficult to establish initially, whether the problems lie in the bones, joints, muscles, or tendons or nerves. We should rule out anatomical or pathological problems in the former four systems before we assume we are dealing with nervous system problems.

It is important to be able to identify the distinct circulating strains and to differentiate between the strains that are merely colonisers and those that have the capacity to produce disease. With this aim various methods of classification of strains or “typing” of H. parasuis have been developed.

When the clinical signs on the farm and the lesions observed in the piglets lead us to suspect that there is a Haemophilus parasuis infection we have to confirm this diagnosis in the laboratory

Haemophilus parasuis is present in all swine producing countries and its prevalence is close to 100% on conventional farms. However, only a percentage of these farms present pathologies associated to the infection.

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.