When the bladder lumen contains only a small volume of urine, contraction of the bladder musculature often quickly seals the
site of disruption. Urine and contrast agents that have accumulated in the peritoneal cavity will be absorbed rapidly and
excreted by the kidneys. If the cat is pollakiuric and has a completely patent urethral lumen, then it might be unnecessary
to use an indwelling transurethral catheter to prevent filling of the bladder with urine. However, if gentle palpation, ultrasonography
or radiography reveal distension of the bladder lumen with urine, then a closed indwelling transurethral catherter system
can be used to minimize distension of the bladder wall. A decision to use antibiotics to prevent bacterial UTI should be made
on a case-by-case basis. Provided clinical and laboratory findings typical of uroperitoneum and post-renal azotemia do not
develop, indwelling catheters may be removed after three to six days. Prior to removal of the catheter, a low-pressure, positive-contrast
cystogram can be performed to evaluate the integrity of the bladder wall.
Clinical experience with uremic patients
Spontaneous rupture of the urinary bladder and clinically significant uroperitoneum secondary to urethral outflow obstruction
of male cats is an uncommon event. It usually occurs in association with overzealous or incorrect attempts to restore urethral
patency. In this setting, patients typically have post-renal uremia associated with varying degrees of fluid, electrolyte
and acid-based imbalances.
Compared to rupture of the urinary bladder in nonuremic cats, patients with post-renal uremia often decline rapidly prior
to bladder rupture. If the obstruction of urine outflow has been present for several days, the integrity of the entire overdistended
bladder wall can be compromised severely.
Initial management should be designed to correct the polysystemic consequences of post-renal uremia, especially hyperkalemia,
acidemia and dehydration. Once the patient's fluid, electrolyte and acid-base disorders have been corrected, patency of the
urethra should be re-established. An indwelling urethral catheter (closed system) can be used to minimize continued loss of
urine into the peritoneal cavity.
If necessary, a peritoneal dialysis type of catheter can be placed in the abdomen to facilitate removal of fluid from the
peritoneal cavity. As soon as the patient's overall condition has been stabilized, the specific nature and timing of additional
diagnostic procedures and surgical or medical therapy should be considered.
When formulating diagnostic and therapeutic plans, care must be used to determine the initial cause(s) of urethral outflow
obstruction, the site and size of the rent in the bladder wall and the time-related trends of change in the status associated
with clinical abnormalities.
Figure 3: Positive contrast cystogram (lateral view) of the abdomen of the dog described in Figure 1 obtained 18 days later.
The reduction in the size of the filling defect in the bladder wall and the marked reduction in irregularity of the mucosal
surface at this site are consistent with healing of the rupture site.
Surgical repair of the large rent in the bladder wall certainly is consistent with conventional knowledge and clinical wisdom.
However, it is of interest that in three out of 14 previously normal dogs with surgically induced untreated bladder ruptures,
spontaneous sealing of 3-centimeter incision sites in the bladder vertex occurred within 45 hours (Burrows et al. Amer J Vet
Res 35: 1083-1088, 1974). Three dogs recovered without the benefit of transurethral indwelling catheterization, fluid therapy
or antibiotic therapy. We also observed remission of uroperitoneum and post-renal uremia in an adult female Beagle with an
induced struvite urocystolith that obstructed the bladder neck. Therapy consisted of restoration of urine outflow by dislodging
the urocystolith from the bladder neck into the bladder lumen, intermittent abdominocentesis, and parenteral administration
of lactated Ringer's solution. Following this experience we also have managed successfully azotemic patients with ruptured
urinary bladders by nonsurgical protocols.
A 10-year-old spayed female Golden Retriever was admitted to the Veterinary Medical Center because of rear limb weakness that
lasted several weeks. The owner's indicated that the dog had difficulty rising to a standing position and was reluctant to
climb stairs. All other body systems were normal. Physical examination revealed that the dog was overweight (body condition
score of 4 points on a 5-point scale), and had musculoskeletal signs consistent with hip dysplasia and osteoarthritis.
Abdominal palpation revealed marked distension of the urinary bladder. Unfortunately, application of excessive digital pressure
to the abdomen by a trainee resulted in rupture of the urinary bladder. This was unexpected, especially since the dog had
no history of urinary tract disease.