Intravenous iodinated contrast media transiently increases urine specific gravity and pH without affecting other...

To evaluate the immediate influence of iopromide, a nonionic iodinated contrast medium for IV use, on urinalysis in dogs undergoing CT scanning, including urine specific gravity (USG), urine dipstick parameters, urinary sediment, and urinary protein-to-creatinine ratio (UPCR).

This prospective, 1-group pretest, post-test experimental study included 30 client-owned dogs undergoing CT between May 1 and July 31, 2024. Cystocentesis samples were collected immediately before and within 30 minutes after IV iodinated contrast medium (IVIC) administration and analyzed by the same laboratory.

Following IVIC administration, median USG increased significantly from 1.046 (95% CI, 1.032 to 1.052) to 1.058 (95% CI, 1.044 to 1.068) and median urine pH increased significantly from 6.25 (range, 5 to 9) to 7 (range, 5 to 9). No significant changes were observed in other urine dipstick parameters, urinary sediment, or UPCR after IVIC administration.

Our study suggests that IV iopromide transiently alters USG and pH in dogs, whereas other urinalysis parameters remain unaffected. Clinicians can rely on most urinalysis parameters, particularly proteinuria and sediment, to guide immediate clinical decisions.

These findings provide practical guidance for accurate interpretation of urinalysis in dogs undergoing CT with contrast media. If USG or pH are critical for patient management, urinalysis should be performed before or on a different day than contrast administration.