A novel high-protein, low-carbohydrate diet enriched with eggshell membrane and omega-3 fatty acids is associated with improvements in pain, mobility, and biomarkers in dogs with naturally occurring osteoarthritis

Introduction Canine osteoarthritis (OA) is a prevalent, chronic disorder causing persistent pain and mobility impairment across a wide age range. Nutritional strategies targeting inflammatory and cartilage degradation pathways are critical components of multimodal OA management. This exploratory study evaluated a novel, complete high-protein diet enriched with eggshell membrane (ESM) and omega-3 fatty acids in laboratory Beagles with naturally occurring OA. Methods Twelve Beagle dogs (mean age 11.0 years) with radiographic and clinical evidence of OA were transitioned to the test diet (37.4% crude protein DM, 1200 mg/kg ESM, 1% EPA DM, 0.66% DHA DM) for a 58-day intervention period. Primary outcomes included technician-assessed pain-related scores and functional impairment scores evaluated using a behavioral assessment tool developed for research colony studies. Secondary outcomes included circulating biomarkers of systemic inflammation (C-reactive protein, CRP) and cartilage degradation (C-terminal telopeptide of type II collagen, CTX-II). Body weight and body composition were monitored using quantitative magnetic resonance (QMR). Results By Day 58, significant progressive improvements were observed in mean cumulative function scores (from 9.4 at baseline to 0.6; p<0.001) and pain-related scores (from 18.7 to 15.6; p<0.001). Concurrent significant reductions were demonstrated in plasma CRP (approx. 59% reduction; p<0.001) and CTX-II concentrations (approx. 28% reduction; p<0.001). Circulating pro-inflammatory cytokines (IL-2, IL-6, TNF-α) showed no consistent changes. Body weight, body condition scores, and QMR lean/fat mass metrics remained remarkably stable throughout the study. Conclusions Feeding a complete high-protein diet enriched with ESM and omega-3 fatty acids was associated with improvements in technician-assessed mobility indicators and reductions in biomarkers relevant to systemic inflammation and cartilage turnover. These changes occurred without meaningful changes in body mass or body composition. While these preliminary findings must be interpreted cautiously due to the open-label, single-arm design, they support further evaluation of this multi-component nutritional strategy as a potential adjunctive strategy in canine OA management.