Dysuria, dealing with the block cat

Katy W. Waddell, RVT, VTS (ECC, Anesthesia)

It can be difficult to tell when a cat is blocked. Inflammation, urgency, and non-productive straining also signs of cystitis when there is not a blockage. The easiest way to tell is by feeling in the belly for a distended bladder. It is often the size of a peach and if there is an obstruction the bladder will be about as hard and firm as a peach. (Normal bladders are usually soft like partly filled water balloons, and non-obstructed inflamed bladders are usually very small or empty).

Mucus, crystals and even tiny bladder stones can clump together to form a plug in the narrow male cat urethra. The opening is so small that it does not take a lot to completely or even partially obstruct urine flow. Only a few drops of urine are produced or sometimes no urine at all is produced.

Male or female, purebred or domestic shorthair, any cat can develop a urinary condition likeFeline Idiopathic Cystitis(FIC), stones, or infection. But when the cat in question is a neutered male, the game changes. Neutered male cats are at the highest risk for developing a much dreaded veterinary emergency: urinary obstruction.

Neutered male cats have incredibly narrow urethras. A neutered male’s urethra is so narrow that involuntary muscular contractions, urethral spasms, can be enough to cause an obstruction. A small stone or a plug made of proteinaceous material and/or crystals can easily become lodged inside the urethra and completely block the outflow of urine.

Approximately 15-20% of feline lower urinary tract cases are caused byuroliths, with the most common form beingcalcium oxalateandstruvite(magnesium ammonium phosphate) uroliths. The majority of uroliths are located in the urinary bladder, but can also form in the kidneys, ureters and urethra.

Treating a blocked cat involves emptying his bladder, relieving the urethral blockage, and dealing with the biochemical abnormalities that have developed. This is typically done by placing a catheter through the urethra and leaving it in place until the bladder has had a chance to remain empty and recover.

A recent study has shown that in some cases, draining the urine from the bladder via needle and syringe (often repeatedly) can also work. Intravenous or subcutaneous fluid therapy,painrelief, medications that promote normal function of the urinary tract, and providing a quiet, stress-free environment are necessary as well. If a cat never regains the ability to urinate normally, surgery can be performed to create a hole in the urethra above the blockage, through which urine can be expelled.

In cats with signs of urinary tract inflammation, blood work is evaluated to check kidney function and to determine if there is any evidence of infection or other systemic illnesses.A urine sample is evaluated for crystals and may be sent in for culture, although bacterial infections of the bladder are uncommon in cats.In cats with recurrent infections, x-rays of the belly may be taken to see if calculi (stones) or other material are present in the kidneys or bladder .

Cats that have urinary obstruction require emergency treatment. Sedation or general anesthesia is needed in all but the sickest patients to allow placement of a catheter into the urethra to flush out the plug or force the stone into the bladder. The bladder is thoroughly flushed and drained through the catheter to remove any remaining sediment. The urinary catheter is then typically left in place for a few days until urethral swelling subsides.Once the catheter is removed, the cat is then evaluated to make sure it can urinate freely before it can be discharged from the hospital.

In cats with bladder stones that can be flushed into the bladder, acystotomy is performed to remove the stones.Cystotomy is also performed in cats with congenital outpouchings of the bladder.

The prognosis for a cat with urinary blockage depends largely on how long the obstruction was present and if it was possible to remove it. The longer the obstruction is present, the more critically ill the cat becomes, and the poorer the outcome. A cat who was blocked once may be predisposed to becoming blocked again. In almost all cases, cats who have had a perineal urethrostomy will not become blacked again. Rarely, complications of the surgery may occur including urinary tract infections or a stricture that would require further surgery.