Canine prostate cancer (PC) is a highly aggressive malignancy. However, in contrast to man, neither standard screening strategies nor curative therapeutic options exist for the companion animal. A prostate-specific membrane antigen (PSMA) screening as molecular marker akin to human PC is currently not available for dogs as data on specific canine PSMA detection are contradictory. To evaluate an antibody for specific canine PSMA detection by western blotting (WB), lysates of three canine prostatic cell lines (CT1258, DT08/40, DT08/46) were comparatively analyzed by WB and mass spectrometry (MS) to the human cell lines VCaP, LnCaP and PC-3. MS analyses of the detected canine proteins confirmed cross reactivity of the antibody clone YPSMA-1 with canine PSMA. The MS analyses of the extracted canine protein bands proved that the YPSMA-1 clone is as well specific for canine PSMA in WB and, thus, represents a reliable tool for comparative PSMA studies.