Osteopathic treatment in horses increases blood concentration of beta‐endorphin, erythropoietin and interleukin‐6

Background: Animal Osteopathy is a manual therapy that utilizes manipulation of body tissues to promote self-healing. Human-based studies suggest that osteopathic treatment induces biochemical changes during and after intervention. Evidence is limited in the veterinary field. Objectives: To evaluate short-term endocrine and molecular markers in horses undergoing an osteopathic treatment. Study design: In vivo randomized controlled trial. Methods: 8 clinically healthy Thoroughbred geldings were assigned to two groups, treated ([OT], n=4 horses) or control ([C], n=4). Blood was drawn from the jugular vein before the treatment, in the middle of the treatment (20 minutes after the beginning of treatment), and at the end of the treatment (40 minutes after the beginning of treatment). The following hormones and markers were measured in the serum by Enzyme-Linked ImmunoSorbent Assay (ELISA), adrenocorticotropic hormone, beta-endorphin, cortisol, dopamine, epinephrine, erythropoietin, growth hormone, interleukin-6, oxytocin, serotonin, and tumor necrosis factor alpha. 18 clinically healthy thoroughbred geldings were assigned to two treatment groups, treated ([OT], n=9 horses) or control ([C], n=9). Beta-endorphin, cortisol, and interleukin-6 concentrations were measured with ELISA kits. Results: No significant difference is noted in cortisol and adrenocorticotropic hormone using catheter and venipuncture. The initial screening shows an increasing trend for beta-endorphin, a significant increase in erythropoietin (0.298 ± 0.109, P = 0.01), and in interleukin-6 (0.0903 ± 0.0398, P = 0.03) in treated horses. No significant changes were noted in serum concentration of adrenocorticotropic hormone, cortisol, dopamine, epinephrine, growth hormone, oxytocin, serotonin, and tumor necrosis factor alpha. The second screening confirmed that beta-endorphin (0.130 ± 0.0436, P = 0.003) and interleukin-6 (0.0765 ± 0.0264, P = 0.005) were significantly increased immediately after osteopathic treatment when compared to controls. Main limitations: Only short-term responses were monitored. Conclusions: A single osteopathic treatment elicited a quantifiable physiologic response in horses, potentially improving animal health and well-being.