Urinary Bladder Stone in a Horse

A 10 year-old gelding presented for a history of frequent urination and blood-tinged urine. The referring veterinarian had analyzed the urine and confirmed the presence of blood. In addition, a CBC and Chemistry was performed on blood collected from the gelding and all parameters were within normal limits. During my initial exam, I sedated the gelding and performed a rectal exam. A plumb-size structure was palpated within the urinary bladder and the gelding became increasingly agitated as the structure was manipulated. Trans-rectal ultrasound noted a 4cm, hyperechoic (bright white) structure within the lumen of the urinary bladder (Figure 1).

Figure 1

Subsequently, a cystoscopy was performed to identify the abnormal structure within the urinary bladder. Once visualized, the structure was identified as a urinary bladder calculi or stone (Figures 2-4). The stone was circular in dimension and the surface was very spiculated which was contributing to irritation of the urinary bladder wall and intermittent hemorrhage from the urinary bladder wall.

Figure 2

Figure 3

Figure 4

Following the cystoscopy, a trans-abdominal ultrasound was performed on the left and right kidneys. Unfortunately, a 5cm stone was visualized within the renal pelvis of the left kidney (Figure 5). Surrounding the hyperechoic (bright white) line is black fluid which most likely consists of urine and a dilated renal pelvis. It is quite likely that this kidney is not filtering blood as it should and nearly non-functional. Fortunately, the right kidney was normal and the horse will be okay as long as the right kidney does not develop a problem!!

Figure 5

The gelding was referred to a surgical facility and the urinary bladder stone was removed successfully. However, the gelding will need regular monitoring for changes in renal function and the presence of new bladder/kidney stones!! The development of kidney/bladder stones in horses is random however horses that consume a diet rich in calcium may be at higher risk.