By Paul Magrath, DVM
Urethral obstruction (UO) is a clinical condition that causes complete blockage of the urethra (i.e. tube the brings urine from the bladder out of the external genitalia) that precludes a cat from urinating normally in the litter box. This is a fairly common disease that almost exclusively affects male cats. This is a medical emergency when happening and can lead to acute kidney failure and death if not treated in a timely manner.
What causes UO? UO is part of a larger complex of a disease called feline lower urinary tract disease (FLUTD). Causes of FLUTD include UTI’s, sterile cystitis, urethral mucus plugs, urethral stones or crystals, swelling, strictures or cancer. Cats with feline idiopathic cystitis (FIC) are at a very high risk of UA. FIC is a chronic, sterile, inflammatory condition of the urinary bladder with no known cause that can eventually lead to UO.
What are the signs of UO? Initial signs of UO can seem rather innocuous which include more frequent trips to the litter box, inappropriate urination in abnormal places and blood in the urine. Cats are still producing urine but in smaller amounts. These signs can last for hours to several days. A lot of people will describe their cats as constipated as it appears they go to the litter box, strain and nothing comes out. In reality, defecation is not the issue, and cats are actually not producing urine. Any male cat that is showing “straining/constipated” signs at home should be evaluated immediately. As symptoms progress and a UO occurs, cats will become more vocal and painful and produce little to no urine. They often become lethargic, loose interest in eating and drinking and start vomiting. If the disease is allowed to advance cat start developing cardiac arrhythmias, signs of toxicity, weakness, altered mentation and start laying on their side with the inability to stand/move. It will eventually lead to potential bladder rupture and death if untreated.
How is UO diagnosed and treated?
UO is typically easily diagnosed on a physical exam performed by your veterinarian. The hallmark sign is a firm, painful bladder felt on palpation. It is important to identify and treat UO as soon as possible.
Bloodwork will be drawn to check general organ function and electrolyte values. Treatment involves sedating and passing a urinary catheter in attempt to dislodge the obstruction. If this is successful, an in-dwelling urinary catheter is sutured in place and the urinary bladder is subsequently drained and flushed. Typically, a cat will end up staying hospitalized for 1-3 days depending on severity of kidney enzyme elevations. Once the kidney enzymes normalize, and the urine is looking clearer, the urinary catheter is pulled and the patient is discharged as soon as he can demonstrate that he can urinate on his own.
Is there anything that can be done to prevent UO?
Although FLUTD tends to be a life-long condition, there are many preventative measures that can be taken to lessen your cat’s chance of getting or relapsing UO. There are several prescription diets on the market that are specifically geared in reducing crystals, dissolving stones and promoting a healthier bladder environment. Weight management is also important as some studies have shown mean body weight was significantly higher in cats with UO. Affected cats are were also more likely to consume exclusively dry food so adding in canned food and encouraging water drinking is also important. Multimodal environmental modifications (MEMO) can also benefit cats with FLUTD. Environmental enrichment including allowing access to climbing structures, providing viewing and resting perches, ensuring adequate numbers of food and water stations, eliminating punishment by owners, increasing positive interactions with owners, increasing access to toys, providing scratching posts and instituting appropriate litterbox management. Feliway is a cat pheromone that has been shown to reduce stress and reduce urinary signs. A helpful website for environmental enrichment can be found here https://www.companionanimalpsychology.com/2019/07/the-five-pillars-of-healthy-environment.html
Repeat offenders of UO should consider having a preventative surgery (Perineal Urethrostomy i.e. PU) to reduce risks of UO occurring in the future.
All in all, UO is a common disorder affected primarily male cats. It is important to identify and treat UO as quick as possible. If your male cat is showing any abnormal urinary signs it should be seen as soon as possible. Although FLUTD is a life long disease, there are many preventative measures that can be done to reduce further risks or relapses. If you have any doubts about your pet please call us, and we are here to help!