The paper observed the influence of the integrated treatment of abortion in mares with the supplement Haemobalans® to replace high-turnover vitamins, amino acids and minerals; and probiotics BF-15® which contains Bifidobacterium bifidum. The aims of this study were to prove the application of Haemobalans and BF-15 as adaptogens during late gestation. We examined 60 healthy adult Thoroughbred mares that were divided into four equal groups (n=15) on the 270 - 300th days of gestation. Test animals received the following treatment: 1 intramuscular injection of Haemobalans in 3 days, in a dose of 1 ml per 45 kg of body weight. BF-15 was also given for 10 days: 20 ml of the oral solution with oats two times per day. Reflex-1 group was treated with the same dose of Haemobalans. Reflex-2 group was treated with the same dose of BF-15. Control animals were also examined. Blood samples were taken before the treatment and two weeks after it. First examination showed the basic level of investigated sources, the last one showed the result of the treatment. The difference between the data (which were obtained before and after treatment) was compared in each group. In case of significant differences between the data of the test group relative to the other three groups, we talked about the reliability of the outcomes. Tissue of placentae were taken after delivery, fixed with neutral formalin and stained with hematoxylin and eosin. Zones of pathological changes were identified. Database of categorical data was created in placental study. Number of cases for markers of placental insufficiency (PI) was determined. In the personal database of one animal the presence of a pathological case was marked (1) and the absence was marked (0). The objective excess of (1) was regarded as PI. The concentrations of glucose, total protein, creatinine, hemoglobin, vitamin B12, ESR, count of lymphocyte and MCHC in the test group were significantly higher: 16.4%; 10.78%; 17.87%; 11.7%; 9.5%; 14.7%; 22.2%, 10.5% higher respectively (P<0.05; in relation on the other groups). In the histological study, placentae of mares which were treated with Haemobalans held proliferation and vascular congestion of villi. Histological changes of placentae in the control group and the reflex-2 group included hyperemia and diapedesis into chorionic villi, protein degeneration of syncytiotrophoblast, shortened villi. Thus, the complex of medications improves metabolism better than the use of a single medicine.