Acta Vet. Brno 2026, 95: 205-214
Non-invasive assessment of renal haemodynamics and tubular injury in diarrhoeic calves: the role of renal resistive index and novel biomarkers
Neonatal diarrhoea is a critical health problem threatening productivity, leading to growth retardation and high mortality rates in the cattle industry. While diarrhoea-induced fluid loss and dehydration can lead to acute kidney injury over time, traditional indicators such as serum creatinine may be slow to detect tubular damage. This study aimed to investigate the diagnostic utility of novel biomarkers such as renal resistive index (RRI) and kidney injury molecule 1 (KIM-1) for early detection of kidney injury in calves with diarrhoea. The study included 30 calves with diarrhoea and 20 healthy calves. Samples were taken before treatment and biochemical indices in blood and urine analysis and KIM-1, neutrophil gelatinase-associated lipocalin (NGAL) and interleukins were analysed using ELISA kits. In addition, non-invasive RRI measurements were performed on the right kidney by Doppler ultrasonography and the data were analysed by t-tests. Urea, creatinine, phosphorus and gamma-glutamyl transferase (GGT) values were significantly higher in the diarrhoea group compared to the control group. Especially in calves with diarrhoea, RRI values were measured as 0.84 on average and showed a significant increase with KIM-1 values (P < 0.001). In addition, positive correlations were also found between RRI values and albumin and IL-8. In conclusion, renal haemodynamic changes in the early stages of diarrhoea can be observed by increasing RRI. In contrast to traditional methods, the combination of KIM-1 and GGT with RRI enables the detection of subclinical tubular damage. This non-invasive and cost-effective approach contributes significantly to the early diagnosis of acute renal failure in calves.
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Funding
This research was financially supported by Afyon Kocatepe University Scientific Research Projects Coordination Unit (BAPK) (21.SAĞ.BİL.02) and was produced from the PhD thesis of the first author.

