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Professional Version

Prostatic and Paraprostatic Cysts in Dogs and Cats


Michelle Kutzler

, DVM, PhD, DACT, Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University

Reviewed/Revised Jun 2020 | Modified Oct 2022

Large cysts are occasionally found within or adjacent to (paraprostatic) the prostate gland. Paraprostatic cysts result from embryologic remnants of the female reproductive tract found in males that become fluid-filled. The signs are similar to those seen with other types of prostatic enlargement and usually become apparent only when the cyst reaches a size sufficient to cause pressure on adjacent organs. Large cysts may result in abdominal distention and must be differentiated from the bladder and from prostatic abscesses.

Medical treatment is ineffective. Castration alone is unlikely to be of benefit but may be indicated after the cyst has been removed. Total excision of the prostatic cyst is the treatment of choice. If complete excision of the cyst is not possible, the remaining portion of the cyst may be filled with a leaf of omentum secured with sutures. This “omentalization” of the cyst will provide internal drainage and lead to resolution. Surgical excision is preferable to marsupialization, because chronic management of the marsupialization fistula is often problematic.

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