Formation of cellular and humoral immunity in obese horses

Obesity in horses is an increasingly important problem in modern veterinary medicine, which is often accompanied by m e tabolic syndrome and can affect the functional state of the immune system. The aim of the study was to investigate the effect of metabolic syndrome on the immune response of horses after influenza vaccination. For the study, 20 adult horses of different sexes and mixed breeds aged 8 to 16 years were selected, 10 of which were clinically healthy and 10 had signs of metabolic syndrome. All horses were routinely vaccinated with the commercially available equine influenza vaccine Bio E quin FT, equine injectable suspension, Bioveta, Czech Republic. Serum samples were collected before vaccination and on the 1st, 2nd, 3rd, 4th weeks after vaccination. As a result of the study, haematological parameters and antibody levels were compared in horses with normal weight and obese horses before and after vaccination. The study showed significant changes in blood parameters depen d ing on the metabolic status of the animals. Obese horses had slightly higher initial levels of leukocytes compared to animals with normal weight, but after vaccination this indicator decreased in both groups. The analysis of red blood cell content showed that in obese horses their level was significantly lower at all stages after vaccination compared to animals with normal body weight. A similar tendency was observed for haemoglobin and haematocrit, which remained 6 – 11% lower in obese animals after vacc i nation. It was also found that vaccination caused an immune response regardless of metabolic status with the formation of speci f ic antibodies. The dynamics of the leukocyte blood count indicates an increase in the level of neutrophils in obese horses, esp e cially on the 7th day after vaccination, and then a decrease on the 14 – 28th day s. Horses with normal weight had a decrease in neutrophil count, indicating an activation of the immune response to the vaccine. An increase in eosinophils in the blood of obese horses was observed on days 21 and 28, as well as a decrease in lymphocytes and monocytes at all stages after vaccination, ind i cating a suppression of immune responses in obese animals. At the same time, these animals showed an increase in the level of globulins and circulating immune complexes, which may indicate the presence of chronic inflammatory processes. Thus, the study confirmed that obesity reduce s the effectiveness of cellular immunity, although the humoral response remains stable. Pro s pects for further research include studying the mechanisms of obesity's effect on the immune system of horses to develop more effective vaccination regimens for obese animals.