Haemato-biochemical and urinary alterations in dogs undergoing iohexol plasma clearance for glomerular filtration rate assessment

Abstract

Iohexol plasma clearance is widely applied for estimating glomerular filtration rate (GFR) in dogs, yet there is limited documentation regarding its immediate effects on routine laboratory parameters. The present study was conducted to evaluate haematological, serum biochemical, and urinary changes in apparently healthy dogs undergoing iohexol-based GFR assessment. Dogs presented for routine health evaluation and vaccination were screened before inclusion. Each animal underwent detailed clinical examination along with hematobiochemical testing, urinalysis, blood pressure measurement, and renal ultrasonography with Doppler assessment. Only dogs considered clinically normal according to IRIS guidelines, thereby excluding acute kidney injury (AKI) and chronic kidney disease (CKD), were enrolled. Six dogs met the selection criteria were included with owner consent. Iohexol was administered intravenously as a single bolus at a dose of 300 mg iodine/kg body weight for plasma clearance estimation of GFR. Blood and urine samples were collected before and after administration to assess possible changes. Statistical comparison of pre- and post-procedure values showed no significant differences in erythrocyte indices, leukocyte counts, platelet numbers, renal biomarkers, serum electrolytes, or urinary parameters. All recorded values remained within accepted physiological limits. Overall, iohexol was well tolerated, and no adverse clinical or haemato-biochemical and urinary alterations were observed. These findings support the safety of iohexol plasma clearance as a practical method for GFR estimation in healthy dogs.