Abstract. In the changing internal and external conditions, maintenance of a constant internal environment – homeostasis – plays a signifcant role in the proper functioning of the organism. Kidneys play a key role in the homeostasis of glucose, in which the sodium-dependent glucose co-transporters contribute to renal glucose reabsorption. Although the localisation of Na+-glucose co-transporters has been extensively covered in animals’ kidneys, the localisation of the transporters in birds’ kidneys is still understudied. The purpose of this study was to immunolocalise the sodium-dependent co-transporters SGLT1 and SGLT2 in kidneys of ostrich chickens of different ages. In the study, kidney material derived from ffteen ostriches was divided equally into three age groups – 1-, 7-, and 14-days-old ostrich chickens. The polyclonal antibodies Rabbit anti- SGLT1 and Rabbit anti-SGLT2 (Abcam, UK) served as primary antibodies and were used together with the IHC kit (Abcam, UK). With the AxioCam HRc camera (Germany) connected to the microscope Zeiss Axioplan-2 Imaging (Germany), the photos were taken and saved to the computer. As the result of the study on ostrich chickens of different ages, SGLT1 was noted to be localised in the renal straight proximal tubules and SGLT2 in the proximal convoluted tubules of nephron. The immunohistochemical locations of sodium-dependent glucose co-transporters revealed to be similar in ostriches’ kidneys of all age groups. The staining for SGLT2 was noted to be more intensive compared to the staining for SGLT1. As avian kidneys have unique morphological and functional features compared to animals, it is recommended that further studies would be performed on the renal tissue of different avian species Keywords: SGLT1, SGLT2, chicken, immunohistochemistry, renal proximal tubules UDС 591.04 591.8 DOI: 10.48077/scihor.25(4).2022.30-35 Comparative Study of Sodium-Dependent Glucose Co-Transporters in Kidneys of Ostrich Chickens Piret Hussar 1,2* , Cristin Allmang 2 , Florina Popovska-Percinic 3 , Tõnu Järveots 2 , Ilmārs Dūrītis 4 1 University of Tartu 50411, 19 Ravila Str., Tartu, Republic of Estonia 2 Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences 51006, 62 Kreutzwaldi Str., Tartu, Republic of Estonia 3 Ss.Cyril & Methodius University in Skopje 1000, 9 Goce Delchev Blvd., Skopje, Republic of North Macedonia 4 Latvian University of Agriculture LV-3004, 8 Kristapa Helmaņa iela, Jelgava, Republic of Latvia SCIENTIFIC HORIZONS Journal homepage: https://sciencehorizon.com.ua/en Scientifc Horizons, 25(4), 30-35 Copyright © The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (https://creativecommons.org/licenses/by/4.0/) *Corresponding author Article’s History: Received: 06.05.2022 Revised: 04.06.2022 Accepted: 05.07.2022 Suggested Citation: Hussar, P., Allmang, C., Popovska- Percinic, F., Järveots, T., & Dūrītis, I. (2022). Comparative study of sodium- dependent glucose co-transporters in kidneys of ostrich chickens. Scientifc Horizons, 25(4), 30-35.