EC Veterinary Science

Human-dog communication is known to influence affect and neuroendocrine function, its impact on slower-moving physiological domains like mineral homeostasis remains unclear. This single-arm pre-post study tested whether a structured, communication- focused intervention (the Pure Love and Harmony [PLH] Formula) could alter hair tissue mineral analysis (HTMA) profiles in companion dogs (Canis lupus familiaris) (*n* = 22) without dietary or supplement changes. Standardized hair sampling and inductively coupled plasma mass spectrometry were performed at baseline and 12 weeks. Primary outcomes included stress-linked electrolytes and ratios (Na, K; Na/K, Na/Mg, Ca/Mg), potentially toxic elements (Hg, Pb, Al), and immune-relevant trace-element indices (Cu/Zn, Fe/Cu). Following the intervention, previously reported behavioral problems were substantially reduced or no longer observed. These visible improvements were accompanied by measurable shifts in mineral levels and ratios toward reference ranges, providing objective physiological support for the observed behavioral changes. Dogs exhibited significant reductions in stress-related ratios, including Na/K and Na/Mg, together with normalization of Ca/Mg. Toxic mercury (Hg) levels also decreased significantly, while the immune-related Cu/Zn ratio shifted favorably toward reference ranges. Importantly, these changes occurred in the absence of nutritional modifications, suggesting that improved owner-dog communication may reduce allostatic load and support mineral homeostasis. These findings extend human-animal interaction research beyond acute hormonal markers by introducing a chronic, integrative biomarker perspective and identifying everyday communication as a potentially low-cost approach to supporting canine welfare. Study limitations include the modest sample size and absence of a control group; future controlled trials are warranted.

Keywords: Human-Dog Interaction; Communication; Hair Tissue Mineral Analysis; Electrolytes; Toxic Elements; Trace-Element Ratios; Canine Welfare

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