Understanding the Feline Urinary System

The feline urinary system is one of the biological systems necessary to maintain the cat‘s health. A cat with urinary tract problems should exhibit physical symptoms to alert the owner that something is wrong. Aspects of cat urinary health can be assessed by measuring the pH level in the cat's urine. Crystals may appear in the cat bladder, ureters, urethra, and kidneys, due to improper diet. Symptoms of urinary problems can include difficulty urinating, loss of appetite, moist areas around the cat penis or vulva, and blood in the urine.

The feline urinary system works to maintain the proper amount of water in the body, as well as the cat's body chemistry.

The organs that make up the feline urinary tract are the kidneys, ureters, bladder and urethra. These organs work together as a complete biological system to eliminate liquid waste from the body. When the urinary system becomes infected or looses functionally it can be detrimental to the feline's health.


Partially digested food is broken down further when it enters the small intestine. From there water and nutrients will be absorbed into the blood stream. The blood stream takes the water to the kidneys which will then filter out any present waste products. This function keeps the feline's body chemistry in balance while it removes toxins.

When the kidneys loose function, waste products (such as BUN and cretinine) that are normally excreted through the kidneys, build up in the feline's blood. Both of these waste products are indicators of how the kidneys are functioning overall. If increased levels of BUN and cretinine are present in a blood test, approximately 70% of kidney function has already been lost. A cat with these results is in CRF (Chronic Renal Failure).


The ureters are two small tube like organs connected to the kidneys. The liquid waste products that have now been filtered out through the kidneys, will pass through the ureters and then dumped into the bladder.

The ureters function within the urinary system is quite simple, but there is a medical condition called an ectopic ureter that can complicate matters.

An ectopic ureter is one that, rather than connecting to the bladder from the kidney, connects directly to the urethra (completely bypassing the bladder). Symptoms of this condition may vary from periodic to continuous incontinence, however, some felines remain asymptomatic. The exact cause of an ectopic ureter is unknown, but it is suspected that some breeds may have a genetic predisposition for the condition.

A urethrocystoscopy is a diagnostic technique used to help identify this physiological abnormality. This is an invasive procedure which requires the veterinarian to insert a small camera into the bladder. This technique allows the veterinarian to check for any physical abnormalities in both the bladder and urethra.

Other available diagnostic procedures include, external imaging techniques, and urethral pressure profilometry.


The bladder is slowly filled with urine, where it will remain, until the cat urinates. As one can see, the bladder has little active functionality, but still serves an important purpose.

A well balanced diet is important to keep your cat's urinary system healthy. An improper diet can lead to urinary tract problems such as strutive crystals. Strutive crystals are comprised of magnesium, and phosphorous, and may collect in the bladder or within the urethra, where they may disable the cat from urinating.

Ask your veterinarian to assist you in planning a diet tailored to suit you cats age and dietary needs. Specialty, and prescription foods are available to assist in managing and/or preventing certain health problems, including those afflicting the urinary tract system. Ask your veterinarian if these foods may be right for your cat.