Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 20 3 2025 09 01 408 416 Parisa Shahbazi 1. Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran 2. Abortion Research Group, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran Monireh Khordadmehr 1. Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran 2. Abortion Research Group, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran Hassan Sadri 1. Abortion Research Group, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran 2. Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran Jafar Shirazi 1. Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran 2. Veterinary Organization, East Azerbaijan Province, Tabriz, Iran Alireza Hakimnejad Veterinary Organization, East Azerbaijan Province, Tabriz, Iran Maryam Moazzen Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran Faeghehossadat Mousavi Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, 516665-1647, Tabriz, Iran 2024 12 16 2025 09 01 Background: Toxoplasma gondii is recognized as one of the most important causes of abortion in small ruminants globally. This study was conducted to evaluate T. gondii in aborted fetuses of sheep and goats in East Azerbaijan Province, northwest Iran. Methods: A total of 62 aborted fetuses were collected from sheep and goat flocks from 2023-2024. The tissue samples following a systematic necropsy were obtained from the brains, livers, and lungs for histopathology and molecular studies. The conventional PCR method using specific primers was performed for molecular evaluations. Additionally, the formalin-fixed tissue samples were routinely conducted for histopathological examinations. Results: T. gondii was present in 40.32% (25/62) of the aborted fetus. In more detail, one, 7, and 15 positive samples were found in the lungs, livers, and brains, respectively. Additionally, one fetus was positive in both the liver and brain, and one fetus was positive in both lung and liver tissues. Histopathological studies demonstrated moderate to severe hyperemia and focal hemorrhage associated with focal to multifocal gliosis, nonsuppurative meningoencephalitis, focal to multifocal mononuclear hepatitis, and nonsuppurative pneumonia. Notably, the Toxoplasma tissue cysts were observed in the livers, but not in the lungs and brains.  Conclusion: The detection of T. gondii genome in the aborted fetuses with high prevalence rate indicates that this infection plays a notable role in the abortion of sheep and goats in East Azerbaijan. Therefore, fundamental management is necessary for the prevention and control of the disease in this region, particularly regarding zoonotic potential. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/4486 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/4486/1447