Oxidative stress (OS) associated with an intense exercise may have a negative influence on equine health. The aim of this study was to determine the effects of endurance races on oxidative and antioxidative status of horses by evaluating changes in reactive oxygen metabolites (d-ROMs), malondialdehyde (MDA), biological antioxidant potential (BAP) and oxidative stress index (OSI) values. The study was carried out on 53 race starts (28 individual horses) competing at different endurance races according to distance (40 and 80 km) and difficulty (easy and demanding). Blood samples were taken before and after the race. Compared to levels of OS serum biomarkers before the race, an increase in values of d-ROMs (P < 0.01), MDA (P < 0.01), and BAP (P < 0.001), and a decrease in OSI (P < 0.001) have been noted after the race. Contrary to other measured biomarkers, BAP did not show significant individual effects of horses. Horses competing at shorter races have shown a significant change in d-ROMs (P = 0.002), BAP (P < 0.001) and OSI (P = 0.004), whereas those competing at longer races in MDA (P = 0.002), BAP (P < 0.001) and OSI (P < 0.001) post-race values. Endurance racing induced changes in values of d-ROMs, BAP and OSI during both easy and demanding races. Changes in all measured OS biomarkers indicate that prolonged aerobic exercise during endurance race could contribute to the imbalance between oxidants and antioxidants in horses, mainly characterised by a pronounced antioxidant response. Biological antioxidant potential was found to be the most reliable biomarker of OS in endurance horses in the present study.

This study aimed to evaluate if exercise-induced acute phase response (APR) occurs in endurance horses in response to the race. The study included 23 horses competing in an endurance competition with a successfully passed clinical examination before the race. Blood samples were collected before the start and within 30 min after the end of the race. Haematological and biochemical tests were performed and correlated to acute phase biomarkers changes. Values of calprotectin and haptoglobin (Hp) decreased after the races compared to values before, while concentrations of ceruloplasmin and albumin recorded a significant increase. Greater changes in calprotectin values were noted in Arabian horses compared to other breeds. Values of Hp showed a significantly greater decrease after longer races. Based on study results, endurance racing induces APR in horses characterised by significant changes in selected acute phase biomarkers. More pronounced changes were noted at races with higher average speeds, suggesting the need for thorough horse monitoring during exhausting races.

During intensive physical activity horses are exposed to thermolysis, electrolyte loss and rising amounts of catabolic products, which results in alterations of biochemical blood parameters due to the horse’s adaptation to metabolic stress. The aim of the present study was to determine the effect of intensive physical activity on serum biochemical parameters in horses competing in 40 and 80 km endurance races. Blood samples were taken from 28 horses before and after the race over four competitions, with a total of 53 samples analyzed. Biochemical parameters studied included creatine kinase, lactate dehydrogenase, aspartate aminotransferase, urea, creatinine, gamma-glutamyl transferase, glucose, triglycerides, cholesterol, sodium, potassium, calcium and magnesium. The extent of change in pre- and post-race values was compared between categories of age, gender, breed, distance and average speed of horses. Creatine kinase and blood glucose values prior to the race were higher than the reference values. Values of renal parameters and parameters of muscle damage increased after the races, and the degree of change was more pronounced at longer racing lengths, as well as at lower average speed. Electrolyte loss was more prominent during longer races. This study demonstrated that endurance races cause evident changes in serum electrolyte concentrations, renal parameters and markers of muscle damage in horses. These changes are observable in horses at both short and long duration endurance races.

Segmental defects of long bones are among the most challenging and debilitating conditions in clinical medicine. Osteogrow-C is a novel osteoinductive device composed of recombinant human bone morphogenetic protein 6 (rhBMP6) delivered within autologous blood coagulum (ABC) with calcium phosphate ceramics that was proven efficacious in preclinical models of spinal fusion. This study aimed to evaluate the efficacy of Osteogrow-C in comparison to that of other osteoinductive therapies in a clinically relevant segmental defect model in rabbits. Segmental defects (15 mm) of rabbit ulna were treated with Osteogrow-C containing different synthetic ceramic particles (tricalcium phosphate [TCP] and TCP/hydroxyapatite 40%/60%), Osteogrow (rhBMP6/ABC), Infuse (rhBMP2/absorbable collagen sponge), and control implants without bone morphogenetic proteins. Defect healing was evaluated by in vivo x-ray scans 4, 8, and 17 weeks after the surgery, and animals were killed after 17 weeks for further radiographical and histological assessment. Evaluation of x-ray images, micro-computed tomography, and histological sections revealed that both Osteogrow-C formulations as well as Osteogrow and Infuse promoted healing of the ulnar segmental defect. However, radiographic scores were higher in animals treated with Osteogrow-C than those for the other used therapies. Moreover, evaluation of in vivo x-ray scans revealed that Osteogrow-C with TCP ceramics induced the most rapid defect bridging. On the other hand, control implants (ABC/TCP and ABC/biphasic calcium phosphate) promoted limited osteogenesis without defect bridging. The findings of this study suggest that Osteogrow-C is a promising safe therapeutic solution for the treatment of large bone defects, providing relief to millions of patients suffering from this debilitating condition.