Longitudinal Changes in Redox-, Immune-, and Neuroendocrine-Related Biomarkers During Low-Intensity Multi-Frequency Bioelectronic Stimulation in Aged Dogs: An Exploratory Pilot Study

Aging is associated with chronic low-grade inflammation, redox imbalance, and altered neuroendocrine regulation. This exploratory pilot study evaluated the feasibility, safety, and longitudinal biomarker changes observed during low-intensity multi-frequency bioelectronic stimulation in six clinically healthy aged dogs (8–11 years). The intervention was conducted for 15 weeks using the QTVeterP/G platform. According to the final institutional study report, the routine intervention was applied daily for 4 h (08:00–12:00) using an animal-use mat installed in each dog’s kennel; a contact-type abdominal belt was used during scheduled analysis and reassessment procedures as an alternative interface for delivery of the same predefined program. Blood was collected at baseline and at weeks 5, 10, and 15. Hematology and plasma biochemistry were used for safety assessment. Expression of SOD1, GPX1, IL-1β, IL-6, TNF-α, IL-2, and IL-10 was evaluated in the blood leukocyte fraction, and plasma SOD1, GPX1, and cortisol were measured by ELISA. Longitudinal changes were analyzed using linear mixed-effects models. No serious adverse events or consistent biochemical toxicity signals were observed. TNF-α, IL-2, and IL-10 expression decreased significantly, whereas IL-1β and IL-6 showed nonsignificant downward trends. SOD1 expression (p = 0.000277), plasma SOD1 (p = 0.000599), and plasma cortisol (p = 0.00227) decreased significantly, whereas GPX1 did not change significantly. Lymphocyte percentage decreased and neutrophil percentage increased over time. Because SOD1 is an antioxidant-response marker rather than a direct measure of oxidative damage, and because direct oxidative-damage endpoints were not measured, the SOD1 findings are interpreted as redox-related biomarker changes rather than evidence of reduced oxidative stress. Likewise, the cytokine profile is interpreted as altered immune-related signaling rather than proof of a generalized anti-inflammatory effect. The small, single-arm, uncontrolled design cannot distinguish stimulation-associated changes from habituation, repeated handling, environmental or seasonal effects, or other time-dependent factors. These findings support feasibility and hypothesis generation and warrant larger randomized, sham-controlled studies of neuroendocrine–immune–redox regulation in canine aging. Individual longitudinal hematological values and NLR are provided in Supplementary Table S3.