We present the case of a five-year-old intact mixed breed male dog with hemorrhagic prostatic cysts. The patient presented with hematuria, dysesthesia, and pain on abdominal palpation. Abdominal ultrasound, hematology, urinalysis, and biochemical evaluation tests were subsequently conducted. Laboratory tests revealed cloudy urine with bacteria, and countless red blood cells. On ultrasound examination, the prostate was severely enlarged, with heterogeneous and reduced parenchyma, surrounding a large cavity filled with anechoic material with moderate cellularity. The urinary bladder was markedly distended and had a round, hypoechogenic structure in the lumen. The patient was hospitalized and had significant, irreversible worsening of the clinical symptoms and died. Subsequently, necropsy of the patient was performed and a histopathological diagnosis of benign prostatic hyperplasia associated with the presence of a prostatic hemorrhagic cyst, prostatitis, and chronic cystitis with an intraluminal blood clot was made. To the best of our knowledge, this is the first report to describe the occurrence of a hemorrhagic cyst in a canine prostate, thus bringing important information from clinical and imaging findings to the veterinary routine.