Initial treatment factors associated with feline urethral obstruction recurrence rate: 192 cases (2004-2010)

Objective-To evaluate the association of treatment factors during initial urinary catheterization (IUC) of cats with recurrence of urethral obstruction at 24 hours and 30 days after catheter removal. Design-Retrospective case series. Animals-192 male cats with urethral obstruction that were treated at an emergency and specialty center from 2004 through 2010. Procedures-Data were obtained from the cats' medical records. Duration of indwelling catheterization, catheterization with a 5F versus 3.5F urinary catheter, treatment with phenoxybenzamine versus prazosin, consistent administration of pain medication, and treatment with meloxicam or antimicrobials during IUC were reviewed for association with rate of recurrent urethral obstruction (rUO). Results-Overall rUO rates were 10.94% (21/192 cats) at 24 hours and 23.57% (37/157 cats) at 30 days after IUC. At 24 hours and 30 days after IUC, rUO developed in 10 of 140 (7.14%) and 20 of 110(18.18%) prazosin-treated cats, respectively, compared with 10 of 46 (21.74%) and 16 of 41 (39.02%) phenoxybenzamine-treated cats, respectively. Reobstruction developed following use of a 5F or 3.5F urinary catheter in 11 of 58 (18.97%) and 7 of 105 (6.67%) cats, respectively, through 24 hours. There was no association between rUO and duration of urinary catheterization, administration of antimicrobials or meloxicam, or consistent administration of pain medication during IUC. Conclusions and Clinical Relevance-At 24 hours and 30 days after IUC, rUO rates in prazosin-treated cats were significantly lower than rates in phenoxybenzamine-treated cats. Reobstruction rate at 24 hours was significantly lower when a 3.5F versus 5F urinary catheter was used.