[Etiology and pathogenesis of papular dermatitis in fattened pigs]

Judging from hitherto knowledge, papular dermatitis of fattened pigs is a polyfactorial disease of idiodisposition nature. It affects only a part of the population of fattened pigs (the so-called susceptible part of population), in the cases of increased contamination of the stable environment with contaminants. The susceptible part of the population includes predisposed individuals unable to cope with the complex contamination stress of large-scale premises for pig fattening. As the concentrations of contaminants in the stable microclimate decrease, papular dermatitis starts declining and the susceptible part of the population of fattened pigs remains latently (free of symptoms) hidden in the population. The main and primary cause of the papular dermatitis of fattened pigs is seen in the predisposed individuals' inability to eliminate quickly and effectively the contaminants (particularly zinc, lead, aflatoxin B1, mercury and cadmium) from their bodies. All the remaining changes, particularly the mutagenic and immunosuppressive effects as well as papular efflorescences on the skin, arise only as secondary phenomena. The papular efflorescences in fact revealed the less resistant and predisposed individuals in the given pig population. In our view there are three factors which play an important role in the resistance of the pigs: the performance of the detoxicating mechanisms, adequate function of the immunity system, and effectiveness of the reparation mechanisms of the genetic apparatus.