Case Study

Ureteroliths and hydroureter in a 12 year old FS Pug with chronic urinary tract infections

The patient is a 12 year old female spayed Pug. This dog had a history of chronic UTIs, which were treated with Baytril. The preliminary ultrasound at the referring DVM revealed hydronephrosis. Initial scan showed moderate hydroureter with dilated thickened ureter and calculus in distal right ureter. Heavy fluid therapy and antibiotics were initiated; the patient was scanned 3 days later. The calculi had not moved, but more hydronephrosis was evident. Initial UA revealed a large amount of calcium oxalate crystals.

The patient is a 12 year old female spayed Pug. This dog had a history of chronic UTIs, which were treated with Baytril. The preliminary ultrasound at the referring DVM revealed hydronephrosis. Initial scan showed moderate hydroureter with dilated thickened ureter and calculus in distal right ureter. Heavy fluid therapy and antibiotics were initiated; the patient was scanned 3 days later. The calculi had not moved, but more hydronephrosis was evident. Initial UA revealed a large amount of calcium oxalate crystals.

DX

Ureteroliths and hydroureter

Sonographic Differential Diagnosis

Multiple ureteral calculi. No free fluid was noted in the abdomen at this time. However, given the reactive omentum surrounding the ureter and right kidney there is a possibility of uroabdomen.

Image Interpretation

Two image sets were presented. The first one was presented on 2/1/12 and the second was on 2/3/12. The urinary bladder revealed minor mural hypertrophy at the right ureteral papilla, suspended debris and approximately 1.5 cm of small sand and calculi consistent with prior passage of nephroliths. The left kidney was uniform at 4.3 cm with minor, corticomedullary mineralization that was non obstructive. Slight pyelectasia was noted. The right kidney was mildly swollen in contour and measured 3.75 cm with mild to moderate pyelectasia that measured 1 x 0.8 cm. The right ureter was dilated and thickened with echogenic, reactive surrounding fat. The lumen measured 0.11 cm. The muscularis of the ureter was hypertrophied. A 0.52 cm calculus was noted in the distal ureter at the level of L4 with surrounding, reactive fat. Many other ureteral calculi were also noted more distally. The right kidney also presented corticomedullary calculus that measured 0.4 cm with surrounding, reactive fat. The right ureteral papilla was thickened at the level of the bladder itself. Passage of prior calculi was likely an issue, likely causing hematuria and infection. The ureter does not appear overtly peristaltic at this time, which is an alarming issue. Two days later, images revealed persistent pyelectasia and swelling with increased reactive omentum around the right kidney and right ureter. More prominent ureteral thickness at 0.32 cm is evident prior to the obstruction. Calculus at the distal right ureter measured 0.96 cm. Therefore, further calculi are likely passing into the right ureters.

Outcome

Right nephrectomy performed 2/9/12, dog doing very well. Current UA still reveals the presence of oxalate crystal.

Comments

The surgeon may be able to milk calculi from the ureter 2.0 cm further into the urinary bladder. However, ureteral transposition may be necessary. Pyelocentesis and culture would be ideal. Stent placement from interventional radiology may be another option in this case. However, the ureteral calculi may be difficult to retrieve in this position, and surgery may be warranted anyway.