Tests for a public affairs programme on German-language national TV showed that almost half of the sausages contained higher levels of bacteria than permitted by law.
The cantonal laboratory of Bern found that 15 of 36 cervelats tested contained elevated amounts of bacteria, exceeding the legal level in some cases by 20 to 40 times or more.
In one case, the level of bacteria was 140 times higher than allowed.
The sausages, coming from 10 cantons, were purchased at small butchers, as well as large grocery retailers.
The results were announced on the Kassensturz programme on Tuesday.
Otmar Deflorin, president of the association of cantonal chemists, told the programme that even with such high levels of bacteria the sausages were not harmful to eat.
But he indicated that the tests demonstrate that hygiene is less than acceptable in the production of some cervelat.
The tests showed the sausages with the highest amount of bacteria were sold by major national retailers such as Coop and Manor.
Fecal bacteria was found in a cervelat sold by Manor, a department store chain.
Manufacturers, many of whom said their own analysis showed no problems, could not explain the bacteria problem.
Several sausage makers informed Kassensturz that they would be reviewing their production processes.
Coop assured consumers that it is working flat out to address the problem.
Among other things, it has slashed the conservation period for sausages in a bid to reduce germs.