Studies of a Naturally Occurring Selenium-Induced Microcytic Anemia in the Przewalski's Gazelle

Due to the fencing of the Przewalski's gazelle (Procapra przewalskii), the microcytic anemia incidence rate continues to increase. The primary pathological symptoms include emaciation, anemia, pica, inappetence, and dyskinesia. To investigate the cause of microcytic anemia ailment in the Przewalski's gazelle, the Upper Buha River Area with an excessive incidence was chosen as the experimental pasture, and the Bird Island Area without microcytic anemia disease was chosen as the control field. Then, the mineral contents in the soil, forage, blood, and liver, as well as the blood routine parameters and biochemical indexes were measured. The findings showed that the experimental pasture had much lower Se content in the soil and forage than the control field (p < 0.01), while the impacted pasture had significantly higher S content in the forage. The damaged gazelles had considerably lower Se and Cu contents and higher S content in the blood and liver than the healthy gazelles (p < 0.01). The presences of Hb, HCT, MCV, and MCH were significantly decreased compared to those in healthy gazelles (p < 0.01). The experimental group had a significantly lower level of GSH-Px activity in their serums compared to the control group (p < 0.01). In the treatment experiment, ten gazelles from the affected pasture were orally administered CuSO₄, 6 g/animal once every 10 days for two consecutive times, and all gazelles were successfully cured. Therefore, it is possible that low Se content in the soil induced an increase in the absorption of S content by forage, leading to the deficiency of secondary Cu in the Przewalski's gazelles, resulting in microcytic anemia.