A fragile histidine triad (FHIT) gene has been studied as a tumor-associated gene in humans. The aberrant FHIT gene and its protein expression have been reported in many types of human cancers. The present study explored the canine FHIT gene structure and its protein expression in the peripheral blood mononuclear cells of healthy dogs by RT-PCR, RACE and immunoblot analysis. The obtained canine FHIT gene contained nine small exons and was located on canine chromosome 20. Furthermore, we identified an alternative splicing form of the FHIT transcript. The deduced amino acid sequence was well conserved between species, and anti-human Fhit antibody could be used to detect the canine Fhit protein. These findings will be useful for future research.