Department of Veterinary Clinical Sciences, Louisiana State University, College of Veterinary Medicine, Skip Bertman Drive, Baton Rouge, LA 70803.
William T. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California Davis, One Shields Avenue, Davis, CA 95616.
Avian Dis. 2020 Dec 1;64(4):478-481. doi: 10.1637/0005-2086-64.4.478.
An adult blue-fronted Amazon parrot (Amazona aestiva) was presented for a 6-wk history of ataxia and weight loss. Complete blood count, plasma chemistry panel, bile acids, and radiographic imaging were considered normal or unremarkable. The patient was hospitalized and supported with subcutaneous fluids, vitamin B complex, meloxicam, enrofloxacin, gavage feeding, and fenbendazole. While hospitalized, the ataxia significantly improved, and the bird began eating on its own and gaining weight. The bird was discharged from the hospital and prescribed enrofloxacin, meloxicam, and fenbendazole to be administered by the owner with recommendations for routine follow-up care. Medications were discontinued before emergent representation; at the time of reevaluation, the patient's condition had deteriorated severely. Given the poor prognosis, the owners elected for euthanasia. No gross abnormalities were noted on postmortem examination. Liver tissue zinc levels measured 125 ppm; normal limit is less than or equal to 25 ppm. Histopathologic changes to the brain were consistent with severe zinc toxicosis demonstrated by vasculopathy of the cerebral arteries and arterioles with multifocal areas of hemorrhage and astrocyte swelling. These findings have been reported in humans and other mammals but not birds. Although the source of this bird's heavy metal exposure is unknown, the high tissue zinc concentrations imply chronic exposure. This case presentation and unusual pathologic findings will be beneficial to the further understanding of avian zinc toxicosis.
一只成年蓝额亚马逊鹦鹉（Amazona aestiva）出现共济失调和体重减轻的 6 周病史。全血细胞计数、血浆化学小组、胆汁酸和放射影像学检查被认为正常或无明显异常。该患者住院并接受皮下补液、复合维生素 B、美洛昔康、恩诺沙星、灌食和芬苯达唑治疗。住院期间，共济失调明显改善，鸟儿开始自行进食并增加体重。鸟儿出院，并开出处方恩诺沙星、美洛昔康和芬苯达唑，由主人给药，并建议进行常规随访护理。在紧急就诊之前，药物已停止使用；在重新评估时，患者的病情严重恶化。鉴于预后不佳，主人选择对其实施安乐死。尸检时未发现明显的大体异常。肝脏组织的锌含量为 125ppm；正常限值为小于或等于 25ppm。脑的组织病理学变化与严重的锌中毒一致，表现为大脑动脉和小动脉的血管病，伴有多发性出血和星形胶质细胞肿胀。这些发现已在人类和其他哺乳动物中报道过，但在鸟类中尚未报道。虽然这只鸟重金属暴露的来源未知，但高组织锌浓度提示其存在慢性暴露。本病例介绍和不常见的病理发现将有助于进一步了解禽类的锌中毒。
