and in caribou (Rangifer tarandus) throughout North America is caused by B. suis biovar 4. B. suis in these animals has been shown to infect cattle. In one study, four of eight cattle penned with 14 naturally infected reindeer became infected with B. suis and were seropositive (Forbes and Tesaro 1993). Although it has not been reported, reindeer likely can transmit brucellosis to other wild mammals, and this could cause confusing serologic responses in bison (Forbes and Tessaro 1993).

A variety of rodents have been reported to be susceptible to infection and to develop disease (Moore and Schnurrenberger 1981), but rodents have not been implicated in the spread of brucellosis in the GYA, perhaps because of inadequate investigation.