Exploring the Most Effective Strategy for Purine Metabolite Quantification in Veterinary Medicine Using LC–MS/MS

Measuring purine metabolites in the serum and urine may help in the early diagnosis of urolith formation, the correction of allopurinol therapeutic dosages, and the evaluation of diet-related alterations. To properly monitor these endogenous compounds and assess their physiological concentration ranges in biological fluids, highly specific and accurate analytical approaches are required. Colorimetric assays are generally used for this purpose, although their cross-reactivity could lead to incorrect determinations. Given the importance of selectivity in detecting endogenous compounds, this study explored the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to enhance uric acid and allantoin measurement in both serum and urine from dogs, as well as urine from bovines. The most effective analytical strategy was identified and successfully applied to an initial batch of samples collected from healthy dogs and bovines. In conclusion, mass spectrometry proved to be a powerful tool for this challenging task, further demonstrating its superior performance in improving clinical laboratory diagnostics, including its valuable applications in veterinary medicine.