The urinary tract consists of the kidneys, ureters, urinary bladder, and urethra. The ureters and urethra are tubes that carry the urine from the kidney to the bladder and from the bladder to the outside of the body. The kidneys filter contents out of the blood such as waste products and liquid. The filtered fluid, or urine, is then sent to the bladder for storage until the animal urinates.
If the urinary tract gets obstructed at any point, the urine will back up in the bladder and then into the kidneys. This will result in renal failure and a buildup of toxins in the bloodstream. Urethral obstruction is a life-threatening emergency and should be addressed by a veterinarian as soon as possible. The longer the cat remains obstructed, the more likely it is to suffer irreversible organ damage or death.
Bladder stones can cause an obstruction to the flow of urine. Also, cats can get urethral obstructions due to a urethral plug caused by a lower urinary tract disease. A number of interconnected factors result in bladder stone formation. The inflammatory reaction within the bladder, a highly concentrated urine, the presence of mineral crystals or stones, and the production of an organic matrix substance all contribute to the disease process. A urethral plug forms within the small area of the urethra from the matrix and debris from the urine that have conglomerated together. Cats that develop lower urinary tract disease tend to form multiple plugs.
The urethra is the most common place for an obstruction of urine to occur because of how narrow the opening becomes at distal end. Because the urethra is narrower in the male cat than it is in the female, male cats are especially prone to urethral obstructions.
