Experimental transmission of Treponema hyodysenteriae from mice to pigs.

Transmission experiments with Treponema hyodysenteriae were conducted with mice and pigs, using laboratory mice as the carrier host. Mice were intragastrically inoculated with T hyodysenteriae and placed in a contact with nonexposed mice or healthy pigs. Contact mice mingled with infected mice at 5 or 180 days after inoculation were shedding T hyodysenteriae in their feces 9 to 14 days after exposure. Pigs exposed directly to infected mouse feces were shedding T hyodysenteriae in their feces after 5 to 17 days of exposure and developed swine dysentery after 11 to 13 days. Transmission of T hyodysenteriae to pigs through direct contact with feces from infected mice indicates that rodents in the field may be a reservoir host and may also be involved in spreading swine dysentery.