Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 17 7 2026 07 01 A rare case report of active Babesia caballi infection in a mare from Gonbad-e-Kavus, Iran 523 525 737445 10.30466/vrf.2026.2070698.4898 EN Amirali Avarseji Department of Clinical Science, Faculty of Veterinary Medicine University of Tehran, Tehran, Iran 0009-0003-6014-9683 Farima Jahromi Department of clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran Barsam Pirali Hamedanee Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran Soheil Mohammadparast Department of Veterinary Medicine, Faculty of Veterinary Medicine, Islamic Azad University, Tabriz Branch, Tabriz, Iran Journal Article 2025 09 08 <em>Babesia caballi</em> is a tick-borne protozoan parasite responsible for causing equine babesiosis, a disease with considerable variation in prevalence across different regions of the world. This report presented a confirmed case of <em>B. caballi</em> infection in a three-year-old mare originating from Gonbad-e Kavus, Iran, highlighting the clinical, laboratory and diagnostic aspects of the disease. The affected mare showed classical clinical signs including persistent fever, generalized weakness, tachycardia and pale mucous membranes, which are indicative of systemic infection and anemia. Laboratory evaluations revealed evidence of hepatic and renal compromise as well as hematological parameters consistent with active inflammatory processes. Microscopic examination of blood smears and molecular techniques such as PCR were employed to confirm the presence of <em>B. caballi</em>, while simultaneously excluding co-infections with other common equine pathogens including <em>Theileria equi</em> and <em>Anaplasma phagocytophilum</em>. This case underscored the critical need to combine conventional diagnostic approaches with molecular methods to achieve accurate detection, effective treatment and appropriate management strategies for equine babesiosis in endemic regions. https://vrf.iranjournals.ir/article_737445_7149a0fa984bd17e705717acc19c3bea.pdf