Ultrasonography as a sensitive and specific diagnostic modality for the detection of ectopic ureters in urinary incontinent dogs.

Abstract

Ultrasonography is a widely available diagnostic modality for the identification of dogs with suspected ureteral ectopia; however published studies detailing its sensitivity and specificity are currently lacking. The aim of this retrospective, descriptive, diagnostic accuracy study was to evaluate the sensitivity and specificity of ultrasonography for the diagnosis of ureteral ectopia in incontinent dogs presenting to a referral institution, using cystoscopy as the gold standard. Medical records of urinary incontinent dogs presenting to a single institution (n = 38) were retrospectively reviewed for the presence of ureteric insertion abnormalities and concurrent urinary tract abnormalities. Ultrasonographic findings were compared with those from cystoscopic examination to determine diagnostic accuracy. The relationship between the presence of concurrent urinary tract abnormalities and ureteral ectopia was assessed using an independent samples t‐test and Mann–Whitney test. Statistical significance was set at P ≤ 0.05. Ultrasonography had a sensitivity of 93.5%, specificity of 100%, and diagnostic accuracy of 95% when identifying dogs with ureteral ectopia. When classifying individual ureters as ectopic or non‐ectopic, sensitivity was 87.8% and specificity was 86.7%. Dogs with ureteral ectopia had significantly more concurrent urinary tract abnormalities on ultrasound than unaffected dogs (P = 0.004). Ectopic ureters were associated with significantly more concurrent ipsilateral upper urinary tract ultrasonographic abnormalities than unaffected ureters (P < 0.001). Ultrasonography performed by an experienced ultrasonographer is a sensitive and specific screening tool for canine ureteral ectopia, which eliminates the need for heavy sedation, general anesthesia, and advanced imaging, although it should not be relied upon as the sole diagnostic modality for the assessment of individual ureters.