CLINICAL FINDINGS
The physical examination revealed a bright, alert, responsive horse. The
rectal temperature was 37.5°C, heart and respiratory rate were within
normal limits. Body condition score was 5/9. Complete blood count (CBC)
including leucocyte differential count (LDC), serum creatinine and urea
as well as symmetric dimethylarginine (SDMA) were within the normal
range on venous blood.
During hospitalisation no polyuria and stranguria could be observed.
Transabdominal ultrasonography (5
Mhz curved array probe, Fa. GE Health Care, Vivid iq) showed both
kidneys to be of physiologic size, shape, and echogenicity. The ureter
could not be seen from this view.
Upon transrectal palpation the bladder was of physiologic size and no
urinary calculus could be palpated. The cranial 15 cm of the right
ureter were palpable and had an extended diameter of about 2-3 cm. The
left kidney could be reached butright kidney could not be palpated.
Transrectal ultrasonography (5 MHz rectal transducer, Fa. GE Health
Care, Vivid iq) demonstrated an approximately 3-4 cm large inhomogeneous
hyperechogenic structure in the area of the caudal pole of the urinary
bladder, which could be traced to the right ureter. The right ureter had
a maximum diameter of 2.3 cm in the orifice area and the lumen was
filled by this hyperechogenic structure in the caudal 10-15 cm. (Fig. 1)
The horse was sedated with detomidine hydrochloride1(0.01 mg/kg bwt intravenously (iv)), butorphanol
tartrate2 (0.025 mg/kg bwt, iv) and
azepromazin3 (10 mg/kg bwt, iv), and a urine sample
was obtained by means of a urinary catheter. The urine showed
physiological characteristics.
Urinalysis revealed a specific gravity of 1026 (reference range\([\text{rr}]\): > 1024), haemoglobinuria,
proteinuria and crystalluria consisting mostly of calcium carbonates and
calcium oxalate monohydrates. No bacteria were cultured from the urine.
A cystoscopy (180 cm long, 10.4 mm diameter flexible endoscope, Fa.
Storz) revealed the urethra and bladder had no signs of inflammation.
Low-grade sediment deposits were visible on the bladder floor. A
pedunculated cauliflower-like mass measuring approximately 2-3 cm was
protruding in the bladder from the right ureteral orifice with periodic
movement (ureteric peristalsis) (Fig.2). The surface was bulging, partly
bloody, smoothly moist and reddend. During the endoscopy the mass
sometimes retracted inside the orifice, coming back into the bladder
vision immediately after. The urine outflow from the ureter was normal
and no mucosal swelling was present around the right ureteral orifice.
At ureteroscopy the mucosa of the right ureter showed no signs of
inflammation, and the small base of the mass could be located
approximately 10 cm cranial of the ureteral orifice (Fig. 3). Urine was
collected from the right and the left ureter. The urine GGT:creatinine
ratio of the left ureter was 19 IU/gKr (rr < 25 IU/gKr) and it
was 25 IU/gKr for the right ureter. Fractional electrolyte excretion
showed slightly increased sodium-, potassium- and chloride-excretion
from both kidneys.
Based on these findings, polypectomy via endoscopic resection utilizing
a snare was performed the next day as an elective procedure to restore
the restricted volume of the ureter and to prevent backflow into the
renal pelvis.