A review of porcine pathophysiology: A different approach to disease

Diseases are often thought to result from a single cause. Although this is sometimes the case, e.g. with a highly virulent infection such as Classical Swine Fever (CSF), more often clinical disease in swine herds results from multiple predisposing factors. This is especially true in modern intensive pig husbandry, in which the role of highly infectious diseases is limited to (nonetheless devastating) outbreaks. More important nowadays are disease s, although associated nith an agent, without a clear pathogenesis. The emp hasis in disease control thusfar has been on treatment, eradication and pre vention. This has been achieved by focusing attention on husbandry factors, such as climate, housing, hygiene, management, and nutrition. Although thi s approach has been successful for a number of diseases, several health pro blems are persistent. There are strong indications that in the latter, intr insic animal factors are important. Successful handling of these problems r equires knowledge of the (patho)physiology of the pig. In this article, sev eral characteristics of pig physiology associated with the occurrence of di sease are described. It appears that the modern (fattening) pig is exceptional among other anima l species in that its cardiovascular system is mismatched to its body weigh t. It is argued that this particular disposition causes relatively minor di sturbances to have major consequences in the pig. This concept of pig physi ology is central to the understanding of the hitherto poorly understood pat hogenesis of several diseases, such as oedema disease.