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First, it is mentioned that the health status of the population of Swiss swines is very good in comparison to other nations due to the activity of the pig health service (PHS) and that in many places the conditions for a reduction of the use of antimicrobials are already there. Then, the activity of the PHS is described. Its success is base on the obstinate implementation of the eradication programs which are already widely used at the present time in several regions of Switzerland and which have attracted interested specialized practitioners. How the renouncement of the use of antimicrobial growth promoters will affect PHS and non PHS herds remains to be determined. A special paragraph lists the reasons why practitioners often have only little access to swine herds. One reason is the lack of competence. This problem should be solved by an intensification of the graduate and postgraduate education. Finally, the argument for a valorization of an applied and problem-oriented research at the faculties should be put forward.

A survey of the prevalence of lung lesions in randomly selected slaughtered swine representative of the Swiss fattening pig population was carried out from May to September 1992 in six large abattoirs. In total 8921 lungs out of 561 herds were examined. Histological investigations were completed in every herd. No gross lesions could be found in 56% of the pigs. The most frequent lesions in individuals were bronchopneumonia (21%) and diffuse pleuritis (21%). Linear scars (9%), focal pleural fibrosis without any pneumonic lesion (2%), pleuropneumonia (1%) and abscesses (1%) were less prevalent. The prevalence of lesions at the herd level was completely different. The lungs of only 14% of the herds were free of any lesions. The main finding at the herd level was a diffuse pleuritis (75%), followed by bronchopneumonia (64%), linear scars (60%), focal pleural fibrosis (20%), abscesses (14%) and pleuropneumonia (9%). In 94% of the herd samples with macroscopically diagnosed bronchopneumonia, the histological lesions were consistent with enzootic pneumonia of pigs.

The EP vaccine Stellamune Myco was tested in 4 different trials. In a first trial, the daily weight increase and the incidence of lung lesions and their degree of severity were compared in non-vaccinated and vaccinated pigs originating from a herd infected with M. hyopneumoniae. The daily weight increases of the vaccinated animals were almost 60 g above that of the non-vaccinated and the number of altered lungs and the severity of the lung lesions was smaller in the vaccinated group. The effects were statistically different. In a second trial, no lesions were observed in 60% of the vaccinated animals. In the non-vaccinated group, the proportion was only about 35%. More severe lung lesions were only present in the non-vaccinated animals. In a third trial, it was observed that the animals originating from infected herds may excrete mycoplasmas despite the vaccination. In a fourth trial, it was determined that SPF piglets were not protected with the vaccination against an infection caused by M. hyopneumoniae.

The establishment of a Porcine Health Service (PHS) was pioneered in the early sixties. After reviewing the history of the formation of the PHS, a few examples of how it stimulated research in several fields in our two faculties are given. The development of the PHS was noticeably slowed down by yearly recurrent "mysterious" outbreaks of actinobacillosis and especially enzootic pneumonia. Epidemiologic investigations have since shown that the reintroductions of these pathogens can occur by airborne transmission. This information filled the last important gap in the battle against these economically and public health important diseases. Simultaneously it became apparent that enzootic pneumonia and actinobacillosis are not merely herd problems but epizootics which can only be eradicated by means of modern disease control legislation. The question is posed whether or not the PHS, which is potentially a valuable tool in the hands of the state veterinarians, should continue to remain under the control of the producers.