ABSTRACT
Despite the importance of animal health, many pig herds worldwide are permanently endemically infected with important pathogens. Examples of such pathogens include porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV-2), Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Haemophilus parasuis, pathogenic Escherichia coli strains, Brachyspira spp. and Streptococcus spp. They cause tremendous economic losses to the pig sector. Unfortunately, during the last decades, pig health has not paralleled the improvement levels as observed in pig production and reproductive performance. Prevalence figures of lung lesions in slaughter pigs for instance are comparable to those of 20 years ago (Meyns et al., 2011). This urges for proper control measures to improve the health of pigs.
