Effectiveness of manual bladder expression in paraplegic dogs.

OBJECTIVE To determine the effectiveness of manual bladder expression in paraplegic dogs by comparing urine volumes measured by use of intermittent catheterization and ultrasonography. ANIMALS 36 paraplegic dogs. PROCEDURES 93 measurements of bladder volume were collected for the 36 dogs. Residual urine volume was determined by use of intermittent urethral catheterization and estimated by use of ultrasonography. RESULTS Manual bladder expression voided a mean of 49% of urine from the bladder in this population of dogs. There was no correlation (R2, 0.06) between the effectiveness of manual bladder expression and body weight. Ultrasonographic estimation of bladder volume had good correlation (R2, 0.62) with bladder volume determined by use of intermittent bladder catheterization, but clinically unacceptable variation for predicting actual bladder volume (mean difference, 22 mL; 95% confidence interval, -96 to 139 mL). CONCLUSIONS AND CLINICAL RELEVANCE Manual bladder expression was ineffective at completely emptying urine from the bladder of paraplegic dogs, but the effectiveness of the procedure was not affected by body weight. Manual bladder expression would likely be a useful procedure to prevent increases in pressure within the bladder. Ultrasonographic estimation of bladder volume could be a useful predictor of actual bladder volume, but it was susceptible to wide variations among dogs, and results should therefore be interpreted with caution.