The purpose of the study was to study the state of the autonomic nervous system and the level of endogenous intoxication markers in animals during pregnancy, physiological and complicated by gestosis and toxic liver dystrophy (hepatosis) and their combination. Materials and methods were used in accordance with the assigned tasks. In the conditions of two farms specializing in the production of milk and located in the Belgorod and Pskov regions, studies were conducted, the object of which were cows of the Red-and-White and Holstein Black-and-White breeds at the age of 3–6 years with a gestational age of 240–250 days. As a result of experimental tests, it was revealed that in cows with moderate gestosis, in addition to traditional hypertension, proteinuria and edema, there is an increase in heart rate variability, tachycardia, hypersympathicotonia, neutrophilocytosis, lymphocytopenia and resorptive endotoxication. With a combination of gestosis and hepatosis, the appearance of new (integral) and strengthening of pathophysiological phenomena specific to each of these pathologies is observed. As a result, a symptom complex of severe pathology is formed with bradycardia, vagotonia, resorptive and metabolic endogenous intoxication, leukogram imbalance with a predominance of young cells, monocytopenia, eosinopenia, more pronounced neutrophilocytosis and lymphocytopenia, as well as a decrease in adaptive potential. The scientific novelty lies in the fact that, according to the data obtained, one of the directions of the progression of preeclampsia (gestosis) may be the development of comorbid pathology. At the same time, the deterioration of the animal's condition is a consequence of the aggravation of each of the associated pathologies and the formation of integral pathogenetic integration in the body. In this case, the choice of therapies should be focused on eliminating or alleviating the manifestation of gestosis and associated pathologies, as well as on leveling the pathogenetic mechanisms of comorbidity.