The physiological parameters that could be reference for trustful diagnosis and prognosis of prostate disorders in dogs were obtained. Thirty six intact male dogs without clinical signs of neither prostatic nor reproductive disorders were allocated according the age in three groups. These animals were submitted to semen manual collection for microbiological exams; transabdominal ultrasonography to evaluate dimensions, ecogenicity, and texture of prostatic parenchyma and aspirative puncture with fine needle for cytological and microbiological analyses. Ultrasonography revealed that the predominant prostatic shape was round with regular surface. Dimensions varied according to age, being small in young animals and large in old ones. There was ...