Introduction. Mycotoxins are a hidden danger in animal and poultry feed. In the search for new methods of combating mycotoxicosis, scientific researchers have increased their interest in natural sources of raw materials (as adsorbents) and the creation of complex preparations based on them. In order to introduce new drugs into production, it is necessary to conduct a complete preclinical study in accordance with modern requirements. The purpose of present study is to investigate the acute toxicity of the complex feed additive “Galluasorb”, based on a natural adsorbent – galloisite. Materials and methods. The article presents the results of the study of acute toxicity with oral administration of 4 doses of a feed additive: 2000, 3000, 4000 and 6000 mg/kg on 2 types of laboratory animals, such as rats and rabbits. There were 6 males and 6 females in each group of rats, and 3 males and 3 females in each group of rabbits. The feed additive was administered to animals once intragastrically through a tube in the form of a suspension. Morphological blood analysis was performed by an automatic Mythic 18 Vet analyzer. Research results, discussion. The analysis of the results of a comparative study of the acute toxicity of a feed additive with a single intragastric administration in rats and rabbits is presented. During 14 days of observation, no death of animals was detected, there were no violations of the general condition and behavior, no negative effects on body weight and morphological parameters of blood (number of erythrocytes, leukocytes, hemoglobin, platelets, lymphocytes, monocytes) were observed. The studied feed additive can be classified according to the degree of exposure to the body to low-toxic substances as toxicity class 4.