Urine volume estimations in dogs recovering from intervertebral disc prolapse surgery.

Ultrasonographic estimations of residual bladder urine volume (expressed as a percentage of the estimated bladder volume before micturition--the "percentage residual urine") and calculations of the amount of urine voided were performed in 15 dogs before and up to 25 days after surgery for thoracolumbar disc prolapse. The percentage residual urine was influenced by the grade of disc prolapse (F = 9.223; p < 0.01). Over the first four days after surgery, there was a significant change in percentage residual urine (F = 3.995; p < 0.05) and an increase in the calculated amount of urine voided (F = 12.305; p < 0.01). It is suggested that ultrasonographic estimation of percentage residual urine may be valuable in monitoring the progress of dogs undergoing treatment for thoracolumbar disc disease.