A study was conducted to evaluate the outcome of urethral obstruction in cats. Forty-five male cats with this diagnosis were admitted to the Clinic for Small Animal Internal Medicine, University of Zurich, between December 2000 and November 2002. Cats were defined as obstructed and included in the study if they could not void urine freely, if calculi were detected in the urethra, or if obvious resistance was experienced with catheterization. Idiopathic urethral obstruction was diagnosed in 24 cats (53%) because no specific cause of the clinical signs could be identified. Thirteen cats (29%) had uroliths, as diagnosed by radiography, ultrasonography, or cystotomy. Eight cats (18%) presented with urethral plugs, diagnosed during urethral catheterization or via urethroscopy. Within the idiopathic group, median durations of hospitalization and indwelling catheterization were 4.5 and 2 days, respectively. After discharge from the hospital, 22 cats had follow-up information, and obstruction recurred in 8 (36%) of these cats. In the urolith group, 6 had calcium oxalate uroliths, 2 had struvite, and 5 had uroliths of undetermined type. Median duration of hospitalization was 6 days, and among the 10 cats that were ultimately discharged, obstruction recurred in 3 (30%). In the urethral plug group, median durations of hospitalization and indwelling catheterization were 4.5 and 2 days, respectively. All 8 were discharged, and obstruction recurred in 3 (43%). Hospitalization and indwelling catheter durations, as well as rate of reobstruction, did not significantly differ between the groups. Of the cats with urethral obstruction for which information was available, 26% died or were euthanized because of their disease. Recurrent obstruction was the most common reason for euthanasia.

COMMENTARY: Fortunately, the rate of urethral obstruction in cats has declined in recent years; unfortunately, this study found that the rate of reobstruction was not any less than it was in a study done 25 years ago. Recommendations for increasing water consumption, increasing the number of litter boxes, and providing resting areas and social contacts were not routinely discussed with the owners of these cats, but this may have helped in some of the cases. The indoor cat initiative (www.vet.ohio-state.edu/indoorcat) provides more helpful information.

Guarded long-term prognosis in male cats with urethral obstruction. Gerber B, Eichenberger S, Reusch CE. J FELINE MED SURG doi:10.1016/j.jfms.2007.06.007.