Clinical and Diagnostic Study of Equine Hemomycoplasmosis in Basrah, Iraq

Background: Equine hemomycoplasmosis, caused by Mycoplasma haemofelis, is an uncultivable parasite that infects the cell wall of erythrocytes and can be transmitted to humans, causing anemia and obvious clinical manifestations in diseased horses, which can end in severe emaciation and death.Objectives: This study aimed to elucidate the clinical and diagnostic aspects of equine hemomycoplasmosis. A deeper understanding of the clinical variations observed in this disease is essential for tailoring effective control strategies to specific needs and challenges. Methods: The study was conducted on 100 horses, aged 2-5 years, of both sexes. Diagnosis of the causative agent was based on cytological examinations (Giemsa-stained blood smears and fluorescent microscopical diagnosis using acridine orange staining). Moreover, the causative agent was confirmed using molecular diagnosis via quantitative real-time polymerase chain reaction (qPCR). However, hematological, biochemical, and gas analyses were also evaluated. Results: The results indicated that the causative organism, a M. haemofelis-like organism, appears coccoid or rod-shaped. It may be observed alone or in a chain, invading the red blood cell (RBC) wall, as seen in Giemsa and acridine dye stains. Additionally, molecular diagnosis was confirmed using qPCR. Hematological analysis results indicated a macrocytic hypochromic anemia with significant differences in clotting factor indices affecting diseased horses. There was also a notable alteration in acid-base balance and anion gap values, reflecting systemic acidemia due to decreased pH in affected horses. Moreover, the biochemical profile of diseased horses showed significant differences compared to healthy controls, with increases in aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total bilirubin, and troponin I. Conversely, levels of total protein, ferritin, and glucose were lower in diseased horses. Conclusion: It was concluded that Hemomycoplasma spp. Infection in all domestic animals and horses remains a significant blood parasitic infection, causing severe and harmful pathological effects and resulting in substantial economic losses for infected animals. It can often be fatal. Therefore, to establish sustainable control programs and ultimately achieve eradication, a multifaceted approach is necessary, focusing on strengthening vaccination efforts, vector control, and improving disease surveillance and diagnostics.