Resolution of a left ureteral stone using electrohydraulic lithotripsy in a thoroughbred colt.

This research article describes a successful case where a urinary stone in a young racehorse was treated via a technique known as electrohydraulic lithotripsy. The horse, suffering from symptoms like high levels of nitrogen in its blood and loss of appetite, was found to have a stone obstructing urine flow in its left ureter.

Background and Initial Treatment

• The Thoroughbred colt was brought in for examination due to azotemia (increased levels of nitrogenous wastes in the blood), and anorexia (loss of appetite).
• A physical examination discovered a ureterolith (urinary stone) in the left ureter of the horse, positioned about 10 centimeters away from the bladder. This stone was blocking about 90% of urine flow when observed via a cystoscopic procedure (examining the urinary bladder with an endoscope).
• An ultrasound scan showed unclear corticomedullary junctions in both kidneys (where the outer, cortex, section and inner, medulla, part of the kidney connect) with the right kidney appearing more reflective echographically.
• A biopsy of the right kidney was done percutaneously (through the skin), revealing chronic interstitial nephritis (an inflammation of the spaces between renal tubules in the kidneys) accompanied by significant medullary interstitial fibrosis (the formation of excess fibrous connective tissue in the kidney).
• Initially, the horse was treated with intravenous fluids, oral sodium chloride, and oral ammonium chloride.

Lithotripsy Procedure and Subsequent Treatment

• Medical treatment was followed by a procedure known as ureteroscopic electrohydraulic lithotripsy. This technique uses a flexible ureteroscope (a tube used to check the urinary tract) to send electrical sparks via a special wire to break down the stone. The procedure was performed through a perineal urethrostomy, a surgical opening created in the urethra via the perineum—the area between the scrotum and anus.
• The surgery was successful in removing the stone from the horse’s left ureter.
• Post-surgery, Klebsiella oxytoca bacteria were found in the urine of the horse. This bacterium is known to cause urinary tract infections in humans and animals. Following the detection, the horse was treated with oral enrofloxacin, an appropriate antibiotic.
• As a result of successful treatment, azotemia was resolved and the horse was able to resume training.