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Urethral obstruction/urinary blockage is a relatively common and life-threatening problem in male cats. The most common signs noted by owners include: lethargy/listlessness or restlessness; in and out of the litter box; straining to urinate; vomiting; crying while in the litter box. Cats that are completely flat out are in the later stages and are critical emergencies; although, at any stage these cats should be considered an emergency and taken to a veterinarian, as soon as possible.

The cause of urinary obstruction in cats is an increased amount of mucous and crystals in the urine and a narrow urethra. Crystal formation is, in part, a function of urinary pH. The two major crystal types are struvite/magnesium ammonium phosphate/MAP and calcium oxalate and are about 50:50 in occurrence rate. Struvites are precipitated in alkaline/basic urine and oxalates in acidic urine. Thus diet modification, for alteration of urinary pH, is a major longterm management strategy in cats that have blocked.

The main complications resulting from delay of presentation to a veterinarian are:

  • increased blood potassium levels (hyperkalemia) resulting in cardiac arrest;
  • kidney damage; and
  • bladder rupture.

The most common of these is hyperkalemia. These cats have an increased risk of death during the unblocking period and a poorer prognosis. An otherwise healthy cat that is presented early for blocking has a good prognosis. For these reasons it is imperative tohave your cat treated immediately.

The typical hospital stay for an uncomplicated blocked kitty is approximately 2-3 days. We generally leave a urinary catheter in for 24 hours and monitor urine output and character closely. Once the catheter is pulled, we watch them for another day or so to be sure that urination is relatively normal and re-obstruction does not occur. Intravenous fluid therapy, antibiotics and other supportive/symptomatic treatments are usually administered during their hospital stay.

Some cats that have had a urethral obstruction never block again and some re-block multiple times. It is impossible to predict which will be recurrent “blockers.” For this reason, owners of these kitties must be careful to watch their cats for signs for the rest of the cat’s life. This must be taken into consideration if the cat is to be left at home alone for extended periods. It is best to board these cats at a veterinary facility during vacations. A surgical procedure, perineal urethrostomy/PU, is available for cats that recur.

Besides diet modification, increasing water consumption is a good long-term management strategy. Providing fresh water often and adding tuna juice to the water are good ways to encourage cats to drink. Some prefer to drink from a running faucet a few times a day. Commercial waterers that provide a constantly re-circulating water source are available. Be creative and find what your cat likes, then stick with it.

Again, it can not be stressed enough that a blocked cat is an emergency. Treatment by a veterinarian early gives the best prognosis and least chance of complications. Please talk to your local veterinarian about diets available for cats prone to urethral obstruction.