Despite the introduction of modern methods of treatment, the creation of new generations of antibacterial agents, and the constant improvement of aseptic and antiseptic methods, the treat-ment of purulent-inflammatory processes remains one of the most complex and urgent problems in veterinary practice. The article presents the results of the isolation of indigenous microbiota from various biotopes of healthy cats, as well as the study of their biological marker properties for the selection of the most optimal strains in probiotic medicines for the control of surgical infections. It was demonstrated that isolated cultures of bifidobacteria and lactobacilli, which we isolated, re-vealed high sensitivity to antibiotics of the β-lactam group (excepting L. acidophilus No. 24, L. planta-rum “Victoria” No. 22, L. rhamnosus No. 5, L. rhamnosus No. 20, and L. rhamnosus No. 26, which showed a significant variability in sensitivity to antibacterial drugs of this group, indicating the great poten-tial of these microorganisms) and resistance to aminoglycosides, lincosamides, and fluoroquin-olones (with the exception of gatifloxacin, which showed high efficiency in relation to all lactic acid microorganisms). The adhesive properties of the isolated lactobacteria and bifidobacteria were var-iable, even within the same species. It was found that the B. adolescentis No. 23 strain of the Bifidobac-terium genus, as well as the L. plantarum No. 8, L. plantarum “Victoria” No. 22, L. rhamnosus No. 6, L. rhamnosus No. 26, L. acidophilus No. 12, and L. acidophilus No. 24 strains of the Lactobacillus genus had the highest adhesive activity. Thus, when conducting a detailed analysis of the biological marker properties of candidate cultures (determining their sensitivity to antimicrobial agents, studying the adhesive properties, and antagonistic activity in relation to causative agents of surgical infection in cats), it was found that the most promising are L. plantarum “Victoria” No. 22, L. rhamnosus No. 26, and L. acidophilus No. 24. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.