Use of polymerase chain reaction in the diagnosis of tuberculosis in cats and dogs.

Samples from four dogs and four cats suspected of having tuberculosis were processed for histopathology, bacterial culture and polymerase chain reaction (PCR). A simple, rapid method for the extraction of DNA from tissue samples was used in two PCR assays designed to confirm the diagnosis of tuberculosis. The PCR assays detected all the culture-positive samples from these animals and no false positive results were obtained. The PCR technique was successful for the direct detection of organisms from the Mycobacterium tuberculosis complex and reduced the time needed for a diagnosis to two days.