Urinary uric acid to creatinine ratio and lactate to creatinine ratio in healthy and pathologic newborn foals

Uric acid to creatinine ratio (Ua/Cr) and lactate to creatinine ratio (L/ Cr) are diagnostic and prognostic biomarkers of perinatal asphyxia in neonatal human medicine. The aim of this work was to investigate urinary Ua/Cr and L/Cr in healthy and critically ill neonatal foals, and their possible diagnostic and prognostic role. Urines were collected by spontaneous micturition from 20 healthy foals within 24 h of age, and daily until day 7. Urines were also collected at admission and between 24 and 36 h after admission from 24 critically ill foals hospitalized within 3 days after birth. Ten foals were affected by perinatal asphyxia and 14 by septicemia. Critically ill foals showed significantly (p < 0.05) higher levels of Ua/Cr during the first 2 days after birth; moreover non-surviving foals (n = 4 with septicemia) hospitalized within 24 h after birth showed significantly (p < 0.05) higher levels compared to survivors (n = 20). Higher L/Cr levels were found in critically ill and non-surviving foals, but no significant differences were found, probably due to the high individual variability. In conclusion, the Ua/Cr ratio could represent an early diagnostic and prognostic marker of disease in newborn foals.