Musculoskeletal disorders are a major cause of lameness in horses, often necessitating innovative regenerative strategies to restore joint function and improve quality of life. This study investigated the effects of platelet-rich plasma (PRP), ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogel (NOLTREX^®) on the behavior of mesenchymal stem cells (MSCs) derived from equine synovial fluid. Synovial fluid samples were collected under strict cytological criteria to ensure viability, followed by in vitro expansion and phenotypic characterization of MSCs. Cultures were supplemented with the tested preparations, and cellular proliferation and viability were evaluated at 24 h, 72 h, and 7 days. PRP significantly promoted MSC proliferation in a time- and dose-dependent manner, with maximal effect at 10%. Hyaluronic acid stimulated growth, most pronounced at 1 mg/mL, while paracetamol induced a concentration-dependent proliferative response, strongest at 100 μg/mL. NOLTREX displayed a biphasic effect, initially inhibitory at high concentrations but stimulatory at 7 days. Ozonized PRP showed concentration-dependent redox activity, with lower doses maintaining viability and higher doses producing an initial suppression followed by delayed stimulation. Collectively, these findings support the therapeutic potential of PRP and related biologic preparations as intra-articular regenerative therapies in equine medicine, while underscoring the importance of dose optimization and standardized protocols to facilitate clinical translation.

Horses maintained under traditional management systems and dependent on natural forages are often exposed to seasonal and compositional variations that can affect metabolic homeostasis. This study examined associations between forage nutrient composition and metabolic–morphometric indicators in horses from four agroecologically distinct regions of northwestern Romania. Eighty-eight horses managed under semi-extensive rural conditions underwent clinical examination, body condition scoring (BCS), cresty neck scoring (CNS), and fasting blood sampling. Forage samples (n = 34) from daily rations were analyzed for fermentable carbohydrate content, while serum insulin, leptin, and adiponectin were quantified using validated equine-specific ELISA assays. Forage composition varied substantially among regions, influencing both endocrine and morphometric outcomes. Horses consuming carbohydrate-rich forages exhibited higher insulin (0.95–219 μIU/mL) and leptin concentrations (925–28,190 pg/mL), accompanied by elevated BCS and CNS scores, whereas adiponectin levels tended to decrease with increasing carbohydrate content. These findings demonstrate that naturally occurring variation in forage quality can significantly influence metabolic regulation in horses managed under low-input, traditional systems. Integrating forage nutrient evaluation with clinical and endocrine assessments provides a practical framework for identifying animals at risk of metabolic dysfunction and guiding nutritional strategies to mitigate the incidence of laminitis and related disorders.

Environmental contamination with heavy metals, resulting from industrialization, urbanization, and agricultural intensification, poses serious ecological and health risks. Horses, due to their grazing behavior and close association with human environments, serve as reliable sentinel species for assessing environmental pollution. This study aimed to evaluate the bioaccumulation of heavy metals and trace elements in different biological matrices of horses—blood, hair, hooves, and synovial fluid—and to investigate their relationship with hematological biomarkers as indicators of physiological stress. Samples were collected from horses raised in anthropogenically influenced areas and analyzed using inductively coupled plasma mass spectrometry (ICP–MS). Hematological parameters were determined with an automated analyzer to assess systemic effects. The results revealed significant variations in metal concentrations among matrices, with keratinized tissues reflecting long-term exposure, while blood and synovial fluid indicated recent contamination. Correlations between elevated metal levels and altered hematological values suggested oxidative stress and adaptive physiological responses. These findings demonstrate the value of multi-matrix biomonitoring in evaluating both environmental quality and animal health. Horses effectively reflect the cumulative impact of heavy metal exposure, supporting their role as bioindicators within a One Health framework that links environmental, animal, and human well-being.

Platelet-rich plasma (PRP) therapy has become a promising method for treating joint conditions in horses, offering potential regenerative benefits. PRP involves concentrating platelets from autologous venous blood, with the release of growth factors such as platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), and vascular endothelial growth factor (VEGF), which stimulate tissue healing and cell regeneration processes. In horses, PRP is frequently used to treat cartilage injuries, synovitis, tendonitis, and adjacent ligament injuries, conditions commonly encountered in equestrian sports. Administering PRP to affected joints can reduce synovial inflammation, promote extracellular matrix regeneration, and alleviate pain associated with cartilage degeneration. Clinical studies have shown significant improvements in joint functionality and a reduction in inflammatory processes in horses treated with PRP compared to those receiving conventional treatment. A large part of PRP's efficacy is due to its mechanism of stimulating angiogenesis and cell proliferation, contributing to the regeneration of damaged joint structures. Although PRP cannot fully restore damaged joint structures, it can slow the progression of degenerative conditions by restoring early homeostasis in the joint environment. It offers a minimally invasive solution that is easy to prepare, using the patient's own resources, and is relatively safe. PRP application in equine veterinary medicine is considered an effective adjunct therapy, particularly in cases where elective treatments such as nonsteroidal anti-inflammatory drugs or surgery have not yielded satisfactory results. However, the variability in PRP composition and the lack of standardized protocols remain challenges in achieving consistent and reproducible results in practice.