Overview of Feline Urinary Bladder Rupture
Bladder rupture is a condition in which the urinary bladder tears and releases urine into the abdominal cavity. The bladder can rupture because of trauma, urinary obstruction, tumors, severe bladder disease, and during catheterization.
Below is an overview on rupture of the bladder in cats followed by in-depth information about the diagnosis and treatment of this condition.
There are no specific breed or sex predilections for this problem. Animals that experience rupture of the bladder can quickly become sick from substances in the urine that leak into the abdomen and get reabsorbed instead of being excreted.
What to Watch For
Lack of appetite
Lack of urine production
Rupture of the bladder rarely occurs without the animal first showing other symptoms of urinary tract disease such as straining to urinate, bloody urine, and inability to urinate.
Diagnosis of Bladder Rupture in Cats
Diagnostic tests may include:
Complete physical examination, including palpation of the abdomen, to rule out other injuries caused by the trauma, or to help diagnose the urinary tract symptoms
Blood tests, including complete blood count and chemistry profile to rule-out other problems and help diagnose a ruptured bladder
Abdominal radiographs (X-rays) to help visualize the size and shape of the urinary bladder
Contrast radiographs to see if urine is leaking out of the bladder into the abdomen
Abdominal ultrasound to look for free fluid in the abdominal cavity and to visualize the walls of the bladder
Abdominocentesis, which is passing a needle through the wall of the abdomen, to help identify free fluid in the abdomen. The fluid may then be “dip stick” tested, or sent to the laboratory for more specific analysis.
Treatment of Bladder Rupture in Cats
Abdominal exploratory surgery with repair of the bladder wall defect is the definitive course of treatment.
Sick animals are given intravenous fluids to help stabilize them prior to surgery. Animals that are too unstable to have surgery may require abdominal drainage until surgery can be done.
Home Care and Prevention
After surgery and discharge from the hospital, your pet should be restricted from excessive activity. He may be given anti-inflammatory medications or pain medications for the first few days to keep him comfortable.
Some cats may be sent home with oral antibiotics for several days if a urinary tract infection is also present or suspected.
Once home, you need to watch your cat carefully for signs of surgical complications, including:
Incision problems such as redness, swelling or discharge
Straining or inability to urinate
Distension of the abdomen
Ruptured bladder associated with bladder stones can be prevented by early diagnosis and treatment of the stones. Bladder rupture associated with trauma can sometimes be prevented. Many traumatic events are true accidents and thus unavoidable. Avoid the chance for motor vehicle trauma by keeping your cat indoors. Other causes of ruptured bladder cannot be prevented.
In-depth Information on Feline Urinary Bladder Rupture
Rupture of the urinary bladder is a serious consequence of major trauma or underlying urinary tract disease and is the most common cause of uro-abdomen, which is the presence of urine within the abdominal cavity, in small animals.
Causes of Bladder Rupture
Motor vehicle trauma is the most common cause of bladder rupture in small animals. The trauma often occurs when a cat is allowed to roam outdoors. If the bladder is full at the time of the accident, the force of the trauma can increase the pressure inside the bladder high enough to exceed the strength of the bladder muscle and a tear results.
Cats with urinary obstruction may strain hard enough to increase bladder pressure above the breaking strength of the bladder wall and cause a rupture. Obstruction can occur secondary to stones that form within the bladder and get lodged in the urethra, or due to masses growing within the pelvic canal that compress the urethra itself.
Tumors of the bladder wall can weaken the wall and lead to rupture.
Severe inflammation of the bladder wall (cystitis) can also cause weakening of the muscle and result in rupture.
Animals with urinary tract symptoms often need to be catheterized or have a needle passed into the bladder (cystocentesis) to get a sample of urine out of the bladder or to try to relieve the urethra of an obstruction. If the bladder wall is severely affected by any underlying condition, these procedures themselves can cause the bladder to develop a tear and leak urine into the abdomen.
Male cats are more likely to have obstruction of the urethra due to stones because the urethra is longer and narrower in males than in females. This may result in a higher risk of bladder rupture. Also male cats can have abnormalities of the prostate gland that cause obstruction of the urethra.
Other causes do not have any breed or sex predispositions.
Once the bladder ruptures, urine begins leaking into the abdomen (uro-abdomen). The urine is the body’s vehicle for getting rid of certain waste products. Normally, the urine is voided from the body through the urethra. When the bladder has ruptured, the animal is not able to completely rid himself of these waste products and they accumulate in the abdomen.
Some of these substances, especially potassium and urea, are reabsorbed through the surfaces of the abdominal organs and can quickly reach excessive levels in the bloodstream. The consequence of the blood levels of these waste products becoming too high is that the animal starts feeling ill.
Elevated blood potassium and elevated blood urea can cause depression, anorexia, vomiting and heart rhythm abnormalities.
As the bladder continues to leak, the abdomen may become distended with free urine. Some animals may continue to urinate almost normally after rupture of the bladder, while others are unable to urinate at all. Animals that are able to urinate even a small amount can make this a difficult diagnosis to make. Eventually, so much urine accumulates in the abdomen the intra-abdominal pressure increases. This can lead to decreased blood supply to the abdominal organs and loss of their function, difficulty in moving the diaphragm to breathe, and eventually death.
Fortunately, except for the cases of traumatic bladder rupture, most animals show symptoms associated with the urinary tract prior to the bladder rupturing. If these early symptoms are addressed and the underlying problem diagnosed and treated, rupture of the bladder can usually be averted. A veterinarian should evaluate any animal showing signs such as difficulty or straining to urinate, bloody urine or inability to urinate.
Animals brought to the veterinarian after a motor vehicle trauma or for urinary tract symptoms should be given a thorough physical examination. Palpation of the abdomen may give the veterinarian clues about the size and shape of the urinary bladder and whether there are large tumors involving the bladder or a large amount of free fluid in the abdomen. A digital rectal examination may reveal intra-pelvic tumors or abnormalities of the prostate gland.
Animals with symptoms of urinary tract disease often have a complete blood count and chemistry profile recommended by the veterinarian. These tests check for abnormal function of the kidneys and liver, electrolyte imbalances, and can indicate if infection or anemia is present.
When your veterinarian begins to suspect that the urinary bladder may be ruptured, abdominal radiographs may help with the diagnosis. They can show the size and shape of the bladder and the presence of abdominal fluid. This test is not very specific for bladder rupture and your veterinarian may still be unsure of the diagnosis after taking these X-rays.
In order to demonstrate that urine is leaking out of the bladder into the abdomen, contrast material can be put directly into the bladder through a urethral catheter or is given intravenously for excretion into the urine by the kidneys. If contrast material is seen free in the abdomen on subsequent radiographs, the diagnosis of bladder rupture is made, although the underlying cause may not be.
Another useful diagnostic tool is the abdominal ultrasound. This test allows the abdominal contents to be visualized and is very sensitive for finding free fluid in the abdomen and for looking at the bladder. Bladder tumors and stones can be seen with ultrasound and a tear in the wall of the bladder can sometimes be found.
Abdominocentesis is a procedure in which a needle is passed through the abdominal wall to retrieve a sample of fluid. This fluid can then be analyzed to see if it is likely to be urine, indicating that a leakage of urine is occurring. The most definitive test for uro-abdomen is to measure the level of creatinine in the abdominal fluid. Creatinine, a large molecule that is normally excreted by the kidneys into the urine, cannot be reabsorbed through the surfaces of the abdominal organs back into the bloodstream. With rupture of the bladder or any other site in the urinary tract, the creatinine level in the abdominal fluid reaches very high levels when compared to a simultaneous blood level.
Animals with high blood potassium levels should be monitored with an EKG for cardiac arrhythmias until the potassium level is back to normal.
In rare cases, the urinary bladder can seal on its own after it has ruptured provided it is kept empty via the use of a urinary catheter. In those cases in which this method of treatment is attempted, the cat must be monitored closely for continued leakage of urine into the abdomen.
In most cases, the only way to treat the ruptured bladder is by surgery. The animal is anesthetized and an incision is made into the rear section of the abdomen. The bladder is examined, biopsy or culture samples are obtained or stones are removed, and the tear in the bladder wall is repaired. The abdomen is flushed thoroughly to remove and dilute the leaked urine and the abdomen is sutured closed.
Prior to anesthesia, some animals may require medical stabilization to make them strong enough candidates for the stress of the surgery. Intravenous fluids may be all that is needed for some animals to help correct their electrolyte imbalances, while others may require fluids and drainage of the urine from the abdomen or diversion of urine through a temporary cystostomy tube. Also, animals that sustained a major trauma may have other concurrent injuries, especially pneumothorax and pulmonary contusions, that may preclude anesthesia and surgical correction until they are under control.
Follow-up Care for Cats with Urinary Bladder Rupture
After discharge from the hospital, the animal must be kept quiet in order to heal properly. Activity must be restricted for a couple of weeks after surgery. Restricted activity means that the animal should be kept confined to a carrier, crate, or small room whenever he cannot be supervised. The cat cannot play or rough-house, even if he appears to be feeling well, and should be confined to a leash when taken outdoors.
Oral antibiotics may be given at home for several days if a urinary tract infection is present or suspected until culture results are complete. Medication should be given as directed by your veterinarian. Analgesics for pain such as butorphanol (Torbugesic®) can cause sedation. Anti-inflammatory medications such as aspirin or carprofen (Rimadyl®) as they can cause upset stomach. Your veterinarian should be informed if any adverse side effects do occur.
The skin incision needs to be monitored daily for signs of excessive swelling or discharge. These can indicate problems with the incision or possible infection. Contact your veterinarian if these occur.
It is common to have some blood in the urine after a repair of a ruptured bladder. This bleeding should resolve within a few days. If it persists or becomes profuse, inform your veterinarian. Straining to urinate is also common after surgery on the bladder, especially if stones were removed from the urethra or bladder. This straining usually decreases over the first few days after surgery. It is important to make sure that the animal is actually getting urine out while he is straining. If no urine is coming out, contact your veterinarian immediately.
In some cases, because of the trauma or the underlying disease of the bladder wall, the bladder may not heal well after repair and can begin leaking urine into the abdomen. The animal may begin feeling poorly again and the abdomen may distend with fluid. If your cat is not improving steadily after surgery or begins to feel badly again, your veterinarian must be informed. If it is confirmed that the bladder is still leaking, another surgery will be required to fix it.