The symptoms of crying, straining, licking the genitals occur because of the pain associated with being obstructed.  Lack of appetite, vomiting, lethargy and collapse may be due to the deleterious effects that urine retention has on the body.   As the bladder pressure increases, the urine is backed up into the kidneys and the cat can go into kidney failure.  The build up of urinary toxins in the blood has direct effects on the lining of the mouth and intestinal tract, which lead to inappetence and sometimes vomiting.  Frequently, the electrolytes in the blood (sodium, potassium and chloride) become very unbalanced and the cat may develop an unstable heart rhythm, which can be fatal. 

In some cases, the bladder may actually rupture and release urine into the abdominal cavity. Urine is very toxic to the organs of the abdomen and will cause a severe peritonitis, which may be fatal as well. 

The cause of the obstruction usually leads back to the development of crystals in the urine as well as the bladder wall becoming inflamed and releasing the blood, white cells, protein and mucus as a result.  Crystal formation is dependant on the pH (acid/base) status of the urine and the concentration of the minerals in the urine.  Certain crystals (which can grow to become sand or stones) are prone to develop in acid urine (pH < 7) while others tend to develop in basic urine (pH >7.0).

Certain types of foods tend to create an acidic urine pH while others tend to develop basic urine.  Knowing this, it is possible to create diets that will reduce the chances of crystal formation.  Unfortunately, not all diets are created equal.  Many diets claim to control this problem when, in fact, they do not. We rely on the Hill’s prescription diets to help maintain the appropriate urine pH and mineral content because of their intense research into the problem and years of clinical experience with their product.   

How do we diagnose Feline Urethral Obstruction?

The clinical symptoms with which the cat is presented give us the indication that there is a problem in the lower urinary tract.  Frequently, we can feel the distended bladder in the belly of your pet.  Usually, the bladder is very painful (as you can imagine it would be from being distended. Based on these indications, we will usually perform examination of the urine (urinalysis) to determine the properties of the urine.  Frequently we will send a sample of the urine to the lab for culture to determine if there is a bacterial infection and what antibiotics may be appropriate to correct the problem.  Radiographs (x-rays) and/or ultrasound are performed to help look for stones or other abnormalities in the belly.  Blood tests will tell us the effects of the obstruction on the kidneys and the rest of the body.

How do we treat urethral obstruction?

Urethral obstruction is a life-threatening problem, which must be dealt with aggressively if we are to save our patient.  Usually, these cats are in great distress and pain, so the first thing we do is to administer pain relief medication.  Next, we may try to relieve pressure in the bladder by removing the urine with a needle.  This can give us some time to fully evaluate the extent of the problem and perform the necessary tests to help ensure the safety of the cat.  Intravenous fluids are administered to help correct dehydration and electrolyte abnormalities.  When the pet has been stabilized, we will sedate him/her and attempt to introduce a catheter into the bladder through the urethra.  If we are successful, we will irrigate the bladder with sterile saline to try and reduce as much of the blood, crystals and debris present.  Usually, we will leave the catheter sewn in place for 24 to 72 hours while we correct any metabolic disturbances.  When the doctor feels it is appropriate, the catheter will be pulled and the cat will be placed under observation to see if it continues to urinate freely. 

It is not uncommon for a blocked cat to re-obstruct within 24-48 hours after the catheter is removed.  If this should happen, we usually try to unblock the urethra again. If the cat remains unblocked, we send him home on antibiotics, drugs for pain, proper diet and sometimes drugs to help dilate the urethra.

If we cannot keep the urethra open without a catheter, then we must consider a surgery called a “perineal urethrostomy”.  In this surgery, the penis is removed, and the urethra is opened directly to the skin near the rectum. This has the effect of widening the urethra, which tends to reduce the chances of further obstruction.  Obviously, this is a radical solution, but sometimes it is the only way in which we can save the cat.  Once it is performed, most cats do very well and can go about living a normal life.

Are there risks involved in treatment?

Any animal with urethral obstruction is a critical patient. It is possible that during of after the initial treatment, the cat may die from complications associated with irregular heart rhythms, electrolyte imbalances or kidney failure. The outcome of treatment depends a lot on how long the cat was obstructed before we were able to intervene. Some cats with urinary obstruction may cause long-term damage to their kidneys.  They may require special drugs, diet and treatment to address this problem for the rest of their lives.  Others may have problems urinating on their own and require some manual assistance (gentle squeezing of the bladder) from their owner in order to urinate.

All of these cats can be subject to recurrence of the problem at any time.  Often, we can reduce the chances of recurrence of the problem through a process of dietary management and surveillance.  Many times, owners do not realize how important the dietary management component of this treatment is.  They switch to alternate feeds once the problem appears to resolve, only to have it recur in short order.  Regular checks of the urine by the veterinarian can help to catch recurrences early in their development and can make management of them more successful. 

What will happen if we do not treat urethral obstruction?

Animals cannot live for long if they cannot urinate.  If your pet is unable to urinate for more than 12 hours on his/her own, it is highly unlikely that the urethra will open up on its own. Unfortunately, most cats will die a very painful death if we cannot treat this problem immediately. 

What can we do to prevent this problem from occurring or recurring?

As mentioned above, proper diet is the key to prevention of the initial and subsequent blockage.  We recommend Hill’s prescription diets for all of our patients as they are all formulated to reduce the chance of crystal formation.  For cats that have had one occurrence of the problem, the appropriate Hill’s diet will be the most important treatment we can prescribe.  We will select the proper formulation for each case based on the type of crystals found in the urine, or the specific type of stone formed. 

Other general preventive measures include:

• Providing plenty of fresh clean water at all times to your cat

• Feeding canned food for the initial few weeks after the obstruction to increase water intake (canned food is 50% or higher in water)

• Keeping the litter box clean and fresh at all times so the cat will not hesitate to urinate in it.