If your cat is straining in the litter box with little or no success, don’t wait — call your veterinarian immediately. Cats with a urethral obstruction, or a blockage in the tube that channels urine from the bladder to the outside, can deteriorate rapidly, and even die if not treated within 48 -72 hours.
Urethral obstruction (UO) typically occurs in male cats, whether they’re neutered or intact, because they have a longer and narrower urethra than female cats have. Bladder stones or urethral plugs, soft mixtures of mucus, protein and cells, can partially or completely block the urethra, so the cat is unable to urinate. Urine accumulates in the bladder, making it painfully distended, and can even back up into the ureters (the tubes between the bladder and kidneys) as well as into the kidneys.
As a result, toxins that are usually eliminated in the urine build up in the cat’s body. The resulting acid/base imbalances and abnormal electrolyte levels, especially hyperkalemia, or high potassium, can ultimately lead to heart failure in as little as 48 hours. Kidney damage may also occur, which is why urinary obstructions in cats are a medical emergency.
Signs there may be a problem
Early on, a blocked or partially blocked cat makes frequent trips to the litter box, straining with little or no success, a sign that’s easy to confuse with constipation. While straining, the cat may cry or howl in pain. If the cat begins to associate the litter box with pain, it may strain in other locations of the house, too. Sometimes, a small amount of bloody urine may be found on the floor. The cat may also lick the genital region excessively.
Once the urine has been blocked for 24 hours or so, toxin buildup can cause vomiting, or the cat may often hide. As the problem progresses, the blocked cat will become weak and lethargic; and will die without treatment. The good news is, if UO is caught early, the survival rate for cats can be as high as 95 percent.
A simple diagnosis
In cats with a history of non-productive straining in the litter box, the diagnosis is usually straightforward: The veterinarian can usually palpate, or feel, a firm, hard bladder in the abdomen. While gently squeezing or expressing the bladder of a normal cat usually results in urination on the exam table, the same procedure on a blocked cat obviously produces no urine.
The veterinarian may also recommend blood work to evaluate kidney function and electrolytes such as potassium, as well as X-rays to look for signs of a urethral stone, urine leakage into the abdomen or any masses. An electrocardiogram (ECG) can also be helpful to check for any cardiac abnormalities.
Treatment usually requires hospitalization
Depending on the cat’s condition, the veterinarian may need to stabilize the patient before relieving the obstruction. This may involve administering medications to correct high levels of potassium to help protect the heart. The patient may also need intravenous fluids to improve hydration.
Cats usually require sedation so the blockage can be removed. The veterinarian will typically place a sterile tube, or catheter, into the urethra and flush the area with sterile saline to dislodge the blockage back into the bladder or out of the urethra.
A catheter usually needs to remain in place for 24 to 72 hours so the veterinarian can make sure blockage doesn’t recur. During this time, the cat may be given pain medications as well as drugs to help prevent the urethra from spasming. In addition, the doctor will generally monitor blood work to make sure electrolytes and kidney values return to normal.
Up to 25 percent of cats with UO may experience it again. Because UO can be a complication of feline lower urinary tract disease (FLUTD) or feline idiopathic cystitis (FIC), strategies to help prevent these conditions can help cats with UO as well. These may include environmental enrichment to reduce stress, good litter box housekeeping, diet modification and tactics to increase water intake.
For cats that continue to block again, surgical correction, known as a perineal urethrostomy, may be an option; but this surgery can have complications as well.
Owners who stay vigilant of their cat’s litter box activities are in the best position to identify a potential UO problem and seek veterinary help, which can be lifesaving, as soon as possible.