**5. Conclusions**

Diseases of the prostate gland are frequent disorders of the aging dogs. The symptoms sometimes are unspecific; however, in case of urination and defecation problems in older male dogs, the enlarged prostate gland must be considered. The andrological examination must include the whole urogenital tract. The Benign Prostate Gland Hyperplasia (BPH) develops slowly and mild symptoms like bloody preputial discharge are typical at the beginning. Using routine diagnostic pathways, starting with a thorough case history followed by clinical examination including digital-rectal palpation and B-mode sonography, the correct diagnosis is quickly made in most cases. Measurement of the CPSE serum concentration can be done; however, the result must be carefully interpreted, considering the age of the dog. When the well-being of the dog is disturbed or sonography of the prostate gland reveals signs of a chronical inflammation, further examinations are necessary. Semen collection with cytological and bacteriological examination of the sperm-rich fraction or prostatic secretion is one possibility. If this is not possible, transcutaneous puncture of cysts can be performed, eventually followed by FNA or biopsy of the diseased tissue. All samples should be examined cytologically and bacteriologically; cytological findings well correlate with FNA findings, and the bacteriological examination should always be combined with a resistance test, since antibiotics in chronical cases, have to be applied for weeks. Prostate gland tumors can only be diagnosed by FNA or biopsy; the search for reliable biological markers and new imaging methods is ongoing. New therapeutical methods such as immunotherapy combined with NSAIDs, targeted noninvasive thermotherapy, *BRAF* gene inhibitors or prostate artery chemoembolization are currently under investigation.
