Bladder Rupture in Adult Horses

Thomas J. Divers • Dominic R. Dawson-Soto • Alexandra J. Burton

Although more common in foals, on rare occasions, bladder rupture can also occur in adult horses. The problem can develop in association with urolithiasis, foaling, prolonged recumbency, or trauma.^1-11 Two cases of ureteral tears have also been reported in adult horses.^12,13 Bladder rupture in mares occurs most commonly due to foaling trauma.^1-5 In male horses, urolithiasis is the most common cause of bladder rupture.^7-9 Bladder rupture has also been reported as a complication following endoscopic electrohydraulic shockwave lithotripsy for treatment of urolithiasis.¹⁰ There is one report of bladder rupture in a 2-year-old horse that had previously had a bladder rupture repair as a foal, the bladder retorn at the same site (old surgical scar) after recovery from routine cryptorchid castration.¹¹

Following bladder rupture, azotemia develops and affected horses become depressed and inappetent.

Clinical signs may not be apparent for several days, depending on how large the tear is and how fast urine leaks into the abdomen. Stranguria may be observed depending on the cause of the rupture. If severe, uroabdomen may produce signs of abdominal discomfort, tachycardia, and abdominal distention. Abdominal distention may not be as apparent in adult horses as in foals. The diagnosis is based on history, rectal examination findings, laboratory results, and findings on urinary US or cystoscopic examination. Postrenal azotemia develops within 24 hours after rupture and is accompanied by hyponatremia and hypochloremia. Unlike uroperitoneum in neonates, hyperkalemia is not a consistent finding. Transabdominal US examination of the abdomen reveals a large amount of free peritoneal fluid. Abdominocentesis yields a peritoneal fluid with a creatinine concentration that is twofold or greater than that of serum; this finding confirms a diagnosis of uroabdomen.

Detection of calcium carbonate crystals on cytologic examination of peritoneal fluid is also diagnostic for uroperitoneum. Endoscopic examination of the bladder should allow determination of the location and extent of the bladder tear. Rarely, uroperitoneum may also develop in some horses without full-thickness disruption of the bladder wall, and it is difficult to establish definitively the cause of uroperitoneum in these cases.⁹

Surgical repair is indicated in horses with large tears in the ventral half of the bladder. In mares, standing surgical repair may be feasible.^3-5 In patients with small dorsal tears or incomplete tears, use of an indwelling bladder catheter (closed system) to keep the bladder small may allow the tear to heal without surgery.^7,9 A temporary ureteral stent may be used to allow healing of ureteral tears.¹² Before surgery, IV fluids (0.9% NaCl) should be administered to correct dehydration, and if severe hyperkalemia is present, NaHCO₃ and/or 5% dextrose administered IV to drive potassium intracellularly. Broadspectrum antibiotics should be administered as prophylaxis against sepsis. If the abdomen is distended, urine accumulated in the abdomen should be removed (e.g., by placement of chest tube or other large catheter through the ventral abdominal wall) before general anesthesia is induced to avoid further compromising respiration.

<< | >>

↑

Source: Smith Bradford P., Van Metre David C., Pusterla Nicola (eds.). Large Animal Internal Medicine. Part 2. 6th edition. — Elsevier,2020. — 2279 p.. 2020

Bladder Rupture in Adult Horses

More on the topic Bladder Rupture in Adult Horses: