Urinary Bladder tumor in a Horse

A 12 year old gelding presented to PHD veterinary services for the complaint of "dribbling" urine and intermittent bouts of urinating blood (hematuria). The horse had been treated with a combination of antibiotics and steroids which had resulted in resolution of blood in the urine however he continued to dribble urine. On presentation the physical exam was normal other than evidence of chronic urinary incontinence based on the accumulation of dried urine over the dorsum of both hind limb pasterns. A rectal exam was performed and a softball-size mass was palpated within the urinary bladder.

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Cystoscopic exam noted several small soft tissue masses leading into the urinary bladder with evidence of active, mild hemorrhage (Figure 1). Once the urinary bladder was entered with the scope, a mass was noted lying underneath the urine that was present in the urinary bladder (Figure 2). The urine was evacuated through the scope revealing a large, soft tissue mass that was firmly attached to the ventral or bottom aspect of the urinary bladder (Figure 3 and 4).

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Urinary bladder neoplasia or cancer is rare in horses. The most common common type reported in horses is squamous cell carcinoma and it commonly associated with hematuria. Other types of cancer include transitional cell carcinoma, lymphosarcoma, leimyosarcoma and fibrous polyps. Management of urinary bladder neoplasia in horses involves surgical resection and possible intra-lesional chemotherapy; however the prognosis is poor for long term survival. This horse will be managed with systemic anti-inflammatory medications to reduce local inflammation within the urinary bladder and the proximal urethra.

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).

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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.

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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!!

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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.