Extraprostatic Prostatic Cysts in Dogs: Clinical Recognition, Surgical Management, and Lessons from a Case Report

Prostatic disorders are among the most common reproductive diseases affecting intact male dogs, particularly those over six years of age. While benign prostatic hyperplasia and prostatitis account for the majority of cases, prostatic cysts, although less common, can become clinically significant when they enlarge and compress surrounding structures¹. Early recognition of these cases allows veterinarians to select appropriate diagnostic imaging and determine whether monitoring or surgical intervention is the most suitable course of action. 

When Should a Prostatic Cyst Raise Concern? 

Prostatic cysts are thin-walled, fluid-filled cavities that may develop within the prostate or externally as extraprostatic cysts. Their development is commonly associated with benign prostatic hyperplasia and obstruction of the prostatic ducts. Progressive ductal obstruction increases intraprostatic pressure, leading to epithelial changes, fibrosis, inflammatory infiltration, increased secretion, and gradual cyst enlargement¹. 

Many cysts remain asymptomatic during the early stages. As they enlarge, however, affected dogs may present with hematuria, stranguria, painful urination or defecation, urethral bleeding, lethargy, anorexia, and flattened feces caused by rectal compression. In advanced cases, large cysts may compress the urethra or ureters, resulting in urinary retention and significant discomfort that can even manifest as lameness¹. 

Building a Logical Diagnostic Plan 

A thorough history and clinical examination remain the starting point for diagnosis. Rectal examination can provide valuable information regarding the size, symmetry, and consistency of the prostate, but its diagnostic value is limited because of the gland's deep pelvic location, particularly in larger dogs¹. For this reason, ultrasonography is essential for evaluating prostatic architecture and identifying cystic lesions. 

When large cysts obscure normal anatomy or cannot be differentiated from the urinary bladder, radiographic evaluation becomes particularly useful. Survey radiography, followed by cystography when necessary, helps define the bladder outline and supports confirmation of large extraprostatic cysts¹. 

A practical example is illustrated by a 12-year-old intact German Shepherd presented with difficulty in defecation, severe abdominal pain, reduced appetite, decreased activity, and progressive weight loss. Rectal examination revealed an enlarged prostate, while ultrasonography identified two large, thin-walled fluid-filled structures within the caudal abdomen. Because their size prevented clear differentiation from the urinary bladder, radiography and subsequent cystography were performed, leading to the diagnosis of extraprostatic cysts. 

Tailoring Treatment to the Patient 

Management depends on both clinical presentation and cyst size. Dogs with mild prostatic enlargement and no clinical signs may simply require periodic ultrasonographic monitoring. Once clinical signs develop, castration is generally recommended, either surgically or pharmacologically with deslorelin acetate implants. Medical therapy may also include hormonal agents or antibiotics when purulent changes are suspected. For cysts exceeding 1 cm in diameter, surgical excision combined with castration is advised^1,2,3. 

In the German Shepherd, surgical management involved aspiration of cystic fluid for cytological and microbiological evaluation, partial resection of the cyst walls, lavage with sterile saline, and omentopexy to reduce fluid accumulation and minimise recurrence. Traditional surgical castration was performed during the same procedure. Microbiological culture was sterile, eliminating the need for targeted antimicrobial therapy. Recovery was uncomplicated, and by the twelfth postoperative day, wound healing was complete. According to the owner, the dog regained normal mobility, activity, and overall vitality within a few days after surgery. 

Conclusion 

Extraprostatic prostatic cysts may be encountered less frequently than other prostatic disorders, but they should remain an important differential diagnosis in older intact male dogs presenting with urinary or defecation difficulties. A structured diagnostic approach that combines clinical examination with appropriate imaging facilitates accurate diagnosis, while treatment decisions should be guided by the patient's clinical status and cyst characteristics. As demonstrated in this case, appropriate surgical management, including cyst resection, omentopexy, and castration, can lead to a favourable clinical outcome while reducing the likelihood of recurrence. 

References 

1. Szczepankiewicz B, Prządka P, Kubiak-Nowak D, Liszka B, Borawski W, Juźwiak Ł, Pasławska U. Extraprostatic cysts in dogs: Case report. Medycyna Weterynaryjna. 2025 Apr 1;81(4). http://www.medycynawet.edu.pl/images/stories/pdf/pdf2025/042025/2025046983.pdf 

2. Khadidja M, Adel A. Canine prostatic disorders. Veterinary medicine. 2017 Sep 29:83-90. https://openventio.us/index.php/VM/article/download/637/571 

3. Polisca A, Orlandi R, Troisi A, Brecchia G, Zerani M, Boiti C, Zelli R. Clinical Efficacy of the Gn RH Agonist (D eslorelin) in Dogs Affected by Benign Prostatic Hyperplasia and Evaluation of Prostatic Blood Flow by D oppler Ultrasound. Reproduction in Domestic Animals. 2013 Aug;48(4):673-80. https://www.academia.edu/download/101805033/rda.1214320230503-1-cycpaq.pdf