Absence of Mycobacterium bovis infection in dogs and cats residing on infected cattle farms: Michigan, 2002.

A cross-sectional field study was performed to evaluate infection in dogs and cats living on farms with Mycobacterium bovis-infected cattle. The purpose was to determine pet infection status and assess their risk to farm families and/or tuberculosis-free livestock. Data and specimens were collected from 18 cats and five dogs from nine participating farms. ELISA testing for M. bovis and M. avium was conducted. Fifty-one biological samples were cultured; all were negative for M. bovis, although other Mycobacterium species were recovered. No radiographic, serological or skin test evidence of mycobacterial infection was found. These negative results may be due to the low level of M. bovis infection in the cattle and the limited duration of exposure of pets to infected cattle residing on the same farm. No evidence was found to indicate that pets residing on M. bovis-infected Michigan cattle farms pose a risk to humans or M. bovis-free livestock; however, precautionary advice for farm owners was provided.