Objective: To evaluate the effect of fenoldopam on renal function in normal dogs subjected to bisection nephrotomy. In addition, effects of bisection nephrotomy on renal function in normal dogs were evaluated. Study Design: Controlled, randomized, blinded experiment Sample Population: Sixteen mixed breed adult dogs Methods: Dogs were paired for sex, body weight, and approximate age and were assigned to one of two groups: fenoldopam (F) or placebo (P). Baseline glomerular filtration rate (GFR), blood urea nitrogen (BUN), serum creatinine (SCr), urinalysis (UA), and urine culture were performed prior to surgery. A left bisection nephrotomy was performed via a standard midline celiotomy. Dogs in Group F received perioperative intravenous infusion of fenoldopam (0.1 ìg/kg/min) for 90 minutes; dogs in Group P received 0.9 % saline (equivalent volume/kg) for 90 minutes. Body temperature, heart rate, respiration, direct arterial blood pressure, and urine volume were recorded during anesthesia. Renal function was assessed by measuring SCr, BUN, and GFR based on quantitative renal scintigraphy using 99mTc-DTPA at 1, 21, and 42 days after surgery. Results: There was no significant difference between groups in physiologic parameters assessed. There was no significant difference in GFR, BUN, or SCr between groups or between operated or control kidneys. Conclusions: Bisection nephrotomy in normal dogs with renal arterial occlusion of 15 minutes and a simple continuous capsular closure does not adversely affect renal function. Clinical Relevance: Further study investigating perioperative effects of fenoldopam in dogs with existing renal dysfunction is indicated. Bisection nephrotomy, as described in this study, does not decrease renal function as measured by BUN, SCr, or GFR. / Master of Science