Evaluation of a Comprehensive Profile of Salivary Analytes for the Diagnosis of the Equine Gastric Ulcer Syndrome

SIMPLE SUMMARY: Equine gastric ulcer syndrome (EGUS) is a common and worldwide-distributed clinical situation with highly unspecific clinical signs, which is diagnosed by gastroscopic examination. Saliva is a biological fluid that has been gaining importance over the years as a diagnostic sample. Because previous studies have shown that some biomarkers change their concentration in saliva in horses with EGUS, the possible usefulness of a profile of biomarkers measured in this fluid for EGUS diagnosis has been studied in this report. A total of 23 salivary biomarkers were measured in horses with EGUS, and values were compared with those obtained in healthy animals and horses with diseases with similar symptoms to EGUS but with a negative diagnosis at gastroscopic examination. A total of 17 biomarkers were increased in saliva from horses diagnosed with EGUS compared to healthy animals, and three of those analytes showed a modest but significant statistical power for discriminating EGUS from other diseases. ABSTRACT: In this report, the measurement of salivary biomarkers as an aid for diagnosis of equine gastric ulcer syndrome (EGUS) was studied. A comprehensive panel of 23 salivary analytes was measured in the saliva of horses affected by EGUS and compared to healthy animals and horses with other diseases clinically similar to EGUS but with a negative diagnosis at gastroscopic examination. A total of 147 horses were included in the study and divided into heathy population (n = 12), the EGUS group (n = 110), and the group of horses with other diseases (n = 25). From the 23 analytes studied, 17 showed increased values in EGUS horses when compared to healthy ones, and uric acid, triglycerides, and calcium were significantly increased in horses with EGUS compared to the group of other diseases. The receiver operating characteristic curve analyses showed a modest but significant discriminatory power of those three analytes to identify EGUS from other diseases with similar symptoms. The discriminatory power enhanced when the results of the three analytes were combined. In conclusion, the results showed that selected salivary analytes could have potential use as biomarkers in horses with EGUS.