EN
Microagglutination test (MA) for the detection of antibodies against Treponema hyodysenteriae was used to assess 783 sera collected from naturally infected pigs from different regions of Poland. It was found that sera from sows displayed high levels of antibodies (titers 128 or more). Similar titers were found in young pigs and less often in piglets. In addition, higher titers of the antibodies were observed in sera derived from pigs which had also antibodies against Leptospira sp. suggesting simultaneous infection of the animals with those two microorganisms. This conclusion was supported by the fact that there was not stated any cross reactivity between T. hyodysenteriae and Leptospira sp.