Analytical validation of aldolase, microalbumin and myeloperoxidase in canine saliva and their evaluation in canine gingivitis

Saliva is a biological fluid that offers potential practical advantages for biomarker assessment in dogs due to its non-invasive nature. This study evaluated aldolase (ALS), microalbumin (mALB), and myeloperoxidase (MPO) in canine saliva using automated assays. All assays showed acceptable analytical performance, with adequate precision (coefficients of variation < 15%), accuracy (coefficients of determination close to 1 after serial sample dilutions), and sensitivity (lower limits of quantification of 5.6 IU/L, 2.05 mg/dL, and 26.3 IU/L for ALS, mALB and MPO, respectively). The effect of gingivitis on these salivary analytes was also assessed. Dogs with gingivitis showed significantly higher salivary ALS and mALB results — ALS, 21.9 (14.2–37.3) IU/L; mALB, 13.15 (5.89–25.71) mg/dL — compared with controls — ALS, 7.65 (2.2-12.23) IU/L; mALB, 3.51 (2.32–5.21) mg/dL— (p < 0.0001). Moreover, increasing gingivitis severity was associated with progressively higher levels of ALS and mALB. In contrast, no significant differences were observed in MPO activity between groups. These findings suggest that ALS and mALB may serve as salivary biomarkers for gingivitis assessment. Further studies are warranted to explore their potential applicability in other local and systemic inflammatory conditions in dogs.