Of 97 dogs which were castrated at the Faculty of Veterinary Medicine, Ghent University between 2003 and 2005 for different indications such as unwanted sexual behavior, prostatic problems, testicular tumors and cryptorchidism; both testicles were examined macroscopically and then submitted for histopathological examination of testicular parenchyma. Thirty eight different breeds were represented in the examined population. Bilaterally normal testicles were found in 46% of the patients. Testicular tumors were found in 29% of the cases and usually occurred in older dogs (mean age 10.9 years). Testicular neoplasms could be subdivided into seminomas (39%), Sertoli cell tumours (14 %), Leydig cell tumors (29%) and mixed tumors (18 %). Testicular neoplasm was incidentally found in 19% of the 27 dogs presented for routine castration. No other testicular pathologies were present in this group. Besides testicular tumors, testicular atrophy (20 %) was the most frequently observed testicular pathology in the population which was examined, whereas inflammation of the testis was very rarely diagnosed (5%).