History
A 3-year-old warmblood gelding was evaluated because of an acute and extensive swelling on the distal two-thirds of the penis. The horse had signs of depression and was in poor body condition. After administration of anti-inflammatory drugs, the swelling was substantially reduced, but the horse's condition continued to deteriorate and the horse was found the next day in lateral recumbency with a heart rate of 60 beats/min. The horse was able to urinate normally. A serum biochemical analysis and CBC were performed and revealed the following abnormalities: hyperkalemia (5.9 mmol/L; reference range, 3.5 to 5.5 mmol/L), low creatinine concentration (0.60 mg/dL; reference range, 0.9 to 2.1 mg/dL), and high creatine kinase activity (4,305 U/L; reference range, 50 to 250 U/L). Packed cell volume (55%; reference range, 35% to 45%) and total protein concentration (7.8 g/dL; reference range, 6.0 to 7.6 g/dL) were high. Four days after the onset of the swelling of the penis and despite aggressive treatment, including IV administration of fluid, the horse continued to clinically deteriorate and was ultimately referred to the hospital. Transabdominal and transrectal ultrasonography of the abdomen was performed (Figures 1 and 2).
Transabdominal ultrasonographic image of the left caudal ventral aspect of the abdomen in a 3-year-old warmblood gelding with a history of severe acute swelling of the penis and increasing hyperkalemia of 4 days’ duration. Top of the image is ventral. The image was obtained with a 4-MHz large convex probe at a depth of 13 to 25 cm. lat = Lateral.
Citation: Journal of the American Veterinary Medical Association 241, 5; 10.2460/javma.241.5.553
Transrectal ultrasonographic images of the bladder of the same horse as in Figure 1. The series of images (A through C) represent the bladder in a sagittal plane slightly abaxial to the right of the horse. Images were obtained with a linear 7.5-MHz probe (depth, 8 cm). Cranial is toward the left; dorsal is toward the top of the series.
Citation: Journal of the American Veterinary Medical Association 241, 5; 10.2460/javma.241.5.553
Determine whether additional imaging studies are required, or make your diagnosis from Figures 1 and 2—then turn the page →
Ultrasonographic Findings and Interpretation
On the transabdominal ultrasonographic image of the abdomen, a large amount of anechoic fluid is present within the peritoneal cavity (Figure 3). Abdominocentesis performed subsequently yielded a translucent yellow fluid with a peritoneal fluid creatinine concentration of 10.5 mg/dL. On the basis of a ratio of peritoneal fluid to serum creatinine concentration > 2:1, a diagnosis of uroperitoneum was made.
Same transabdominal ultrasonographic image of the abdomen as in Figure 1. Notice the large amount of free anechoic fluid.
Citation: Journal of the American Veterinary Medical Association 241, 5; 10.2460/javma.241.5.553
Transrectal ultrasonographic images of the bladder reveal a full-thickness tear in the bladder wall (Figure 4). Furthermore, suspended hyperechoic particles are evident. During ultrasonographic examination, these particles were seen traveling from the bladder to the abdominal cavity through the defect, indicating the flow of urine into the abdomen. Scanning the bladder, from left to right, with the probe on the long axis of the bladder revealed a 3-cm-wide tear, centered slightly to the right of the midline.
Same transrectal ultrasonographic images of the bladder as in Figure 2. Notice the full-thickness tear in the ventral aspect of the bladder (arrow) oriented dorsoventrally and laying on the cranial edge of the pubis (line). In all areas viewed, the bladder wall has a thickness of > 1 cm (length of double-headed arrow); edema is evident in portions of the bladder wall (dashed arrow). Since the image is slightly abaxial to the right of the horse, the urethra is not visualized in the caudalmost view (C).
Citation: Journal of the American Veterinary Medical Association 241, 5; 10.2460/javma.241.5.553
Comments
In the horse of the present report, findings on transabdominal ultrasonography and abdominocentesis were diagnostic for uroperitoneum. Causes of uroperitoneum in adult horses include rupture of the bladder, urethra, or ureter.1 Transrectal examination of the bladder was possible in the case described in the present report because of the size of the horse. Direct visualization of urine flowing through the tear confirmed the diagnosis. In foals, a retrograde injection of agitated sterile saline (0.9% NaCl) solution into the bladder via a urethral catheter, assisted by transabdominal ultrasonography, may reveal gas bubbles leaking from the defect into the peritoneal cavity and help in the diagnosis of uroperitoneum.1 Endoscopy1 is also an alternative method to evaluate the ureters, bladder, and urethra but was not used in the case described in the present report. Given that ultrasonographic examinations of the kidneys, ureters, and urethra were not performed, lesions in these parts of the urinary tract could not be excluded. Because of financial constraints, surgical laparoscopic repair2 of the rupture was not attempted and the horse was euthanized. The cause of the rupture remains unclear. Although there was no sign of stenosis of the urethra at necropsy, severe transient constriction of the urethra due to the swelling of the penis could have led to urethral obstruction and bladder rupture, as described in a previous case report describing a gelding.3
1. Traub-Dargatz J, McKinnon A. Adjunctive methods of examination of the urogenital tract. Vet Clin North Am Equine Pract 1988; 4:339–358.
2. Walesby H, Ragle C, Booth L. Laparoscopic repair of ruptured urinary bladder in a stallion. J Am Vet Med Assoc 2002; 221:1736–1741.
3. May KA, Kuebelbeck KL, Johnson CM. Urinary bladder rupture secondary to penile and preputial squamous cell carcinoma in a gelding. Equine Vet Educ 2008; 20:135–139.
