Renal Perfusion in Healthy Horses: A Feasibility Study With Contrast-Enhanced Ultrasound.

This study assessed the feasibility of contrast-enhanced ultrasound (CEUS) for evaluating renal perfusion in horses and compared perfusion parameters between age groups. In a prospective study, eight healthy horses were divided into young (3-5 years, n = 4) and old (16-17 years, n = 4) groups. All animals underwent B-mode, Doppler ultrasonography, and CEUS of the right kidney after an intravenous bolus of SonoVue (0.02 mL/kg). Qualitative analysis assessed contrast kinetics, whereas quantitative parameters (peak intensity, time to peak [TP], area under the curve, and wash-out time) were obtained from time-intensity curves in the renal cortex and medulla. The technique was safely performed in all horses, and the 0.02 mL/kg dose proved optimal for achieving adequate renal enhancement and consistent quantitative measurements. Quantitative analysis revealed a significantly longer TP in the renal cortex of older horses compared to young ones (p = 0.03), suggesting an age-related reduction in perfusion velocity. No other parameters showed significant differences. CEUS proved to be a feasible and safe method for assessing renal perfusion in horses. The prolonged cortical TP in older animals indicates that CEUS may be a sensitive tool for detecting early, subclinical perfusion changes associated with aging, warranting further investigation in horses with renal disease.