Introduction

The urethra is a common area of urologic dysfunction in male dogs for conditions such as strictures, obstructive urolithiasis, rupture, neoplasia and incontinence. Examination of the male urethra is difficult and often requires a diagnostic imaging work-up. CT Urethrography (CTU) is a promising technique that we have developed.

Objective

This study was undertaken to establish the diagnostic quality of CTU studies in the evaluation of the canine urethra.

Methods and Materials

This is a retrospective case series. Medical records from the University of Edinburgh were reviewed to identify male dogs presenting with lower urinary tract symptoms receiving a CTU study under our protocol. Images were blindly reviewed scoring the quality of the study, number of CTUs performed and the urethral width at different levels (0– Collapsed; 1- Partially Filled; 2- Distended; 3- Stenotic; and 4- Obstructed) for transverse, sagittal and curvilinear studies. Results were correlated with the final clinical diagnosis.

Results

Twenty-one (21) male dogs with a diagnostic quality CTU study were included. Urethral width was scored similarly across different locations and image orientations. There was complete correlation between urethral width grades 3 & 4 and clinically diagnosed stenosis and obstruction. 11/22 dogs (50%) required 1 CTU study, 9/22(41%) dogs required 2 CTU studies; and 2/22 (9%) required 3 CTU.

Conclusion and Discussion

CTU gives an accurate assessment of the urethral lumen in the male dog allowing reliable and time-efficient diagnosis of stenotic and obstructive conditions. Additional reconstructions in sagittal and curvilinear planes were helpful for the confidence of diagnosis, but did not change scoring results.