Balloon dilation offers option for canine urethral blockages

Balloon dilation is being trialled by RCVS Specialists at the University of Edinburgh’s Hospital for Small Animals for dogs with urethral narrowing or blockages, as a potential alternative to urethral stents or cystotomy tubes in selected cases.

The technique, delivered under real-time imaging guidance, aims to restore urethral patency without leaving a stent. Clinicians believe this may translate into practical advantages for both patients and owners, including:

• Minimally invasive, supporting faster recovery times
• Lower cost, potentially improving affordability for owners
• Potentially reduced risk of long-term urinary incontinence, by preserving natural muscle control of the urinary tract
• Possibly lower risk of recurrent urinary tract infection, as no foreign material is left within the urethra

Case example

A nine-year-old male neutered dog that previously received definitive radiotherapy for prostatic carcinoma at the Hospital’s Oncology Service was referred to colleagues in the Internal Medicine Service. 

The dog had progressive lower urinary tract signs, including stranguria and an inability to empty the bladder effectively. Clinical assessment and ultrasonography identified a large, firm bladder post-urination, consistent with incomplete voiding resulting in overflow incontinence.

A CT scan confirmed progression of the prostatic tumour with partial urethral obstruction. Concurrent bacterial cystitis was diagnosed and treated, and medical therapy was initiated to reduce urethral spasm without success. Given the clinical priorities—particularly the need to maintain continence for this dog—stenting was considered inappropriate in this individual.

Under general anaesthesia and fluoroscopic guidance, clinicians used a urethral balloon dilation catheter to distend the obstructed area and gently dilate the urethra. 

Dilation success

Fluoroscopy confirmed improved patency during the procedure. The patient was discharged the following day with ongoing medical management for urethral relaxation.

Within five days, the owners reported a marked improvement in urine stream and reduced straining, alongside resolution of urinary incontinence. The dog maintained a good quality of life for a further 14 weeks, before recurrence of obstruction prompted the owners to opt for humane euthanasia.

The Internal Medicine Service at the Hospital for Small Animals is one of the largest groups of its kind in the UK.  It accepts referrals in all areas of small animal internal medicine. For more information about the service, or to refer a patient with a urethral blockage, contact hfsareception@ed.ac.uk