In normal functioning, the blood-aqueous barrier provides ophthalmic homeostasis. The study of the blood-aquatic barrier is carried out in several main directions, one of which is an experimental animal study. In this work, the blood-aquatic barrier’s permeability with tetracycline group drugs in pathological and normal conditions is studied using the example of three groups of laboratory rabbits. Group 1 – clinically healthy animals; group 2, group 3 – sick animals with experimentally induced pathology. Rabbits of the first and second groups were administered orally three times, with an interval of 8 hours, a tablet form of tetracycline at the rate of 25 mg/ kg of body weight, rabbits of the third group were given 3% tetracycline 3 times a day for the lower eyelid. Animals’ clinical examination included palpation of the examination, affected organs, and thermometry. Biological fluids (intraocular fluid and blood) were taken from the studied animals. The article presents the data of studies of tetracycline concentration, hematological parameters of blood serum, and biochemical parameters of blood serum of the studied animals. On the 9th day after the introduction of the Staphylococcus aureus suspension, clinical recovery occurred in all animals in the second and third groups, which was expressed by normalization of the animals’ general condition, the number of respiratory movements, pulse rate, stabilization of body temperature was also within the limits. In the visual analyzer, the absence of inflammatory phenomena in the iris, cornea, and conjunctiva was observed in 2 animals of the second group.