Kaye Sarrah, Johnson Shawn, Rios Carlos, Fletcher Daniel J
Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA.
The Marine Mammal Center, Sausalito, CA, USA.
Vet Clin Pathol. 2017 Dec;46(4):589-596. doi: 10.1111/vcp.12540. Epub 2017 Sep 13.
Prepatent Otostrongylus arteritis results in hemorrhagic diathesis in free-ranging Northern elephant seals (Mirounga angustirostris) attributed to aberrant larval migration of the lungworm, Otostrongylus circumlitus. Clinical signs are often nonspecific, including lethargy, anorexia, and blepharospasm, but can progress to spontaneous frank hemorrhage and death within 72 hours of onset. Previously published case reports describe coagulopathy with prolonged PT and APTT, normal to elevated platelet counts, normal antithrombin concentrations, and low concentrations of fibrinogen degradation products. Disseminated intravascular coagulation was proposed as the cause of hemorrhage, but is inconsistent with some of the reported clinicopathologic changes.
The purpose of this study was to compare plasmatic coagulation and fibrinolysis in healthy and Otostrongylus-affected elephant seals, in order to identify potential therapy. We hypothesized that hyperfibrinolysis contributed to hemorrhage in these cases.
Citrated plasma samples were collected from 3- to 4-month-old Northern elephant seals in a wildlife rehabilitation hospital. The sampled population included 25 healthy, prerelease seals and 32 clinically ill seals diagnosed with presumptive Otostrongylus arteritis. Twenty-one of the included seals had Otostrongylus infestation confirmed at necropsy. Standard coagulation tests and plasma thromboelastography were performed for a complete assessment of coagulation and fibrinolysis.
Northern elephant seals with definitive Otostrongylus infestation were hypocoagulable and hypofibrinolytic compared to healthy controls.
Results were most consistent with disseminated intravascular coagulation. Treatment with antifibrinolytic drugs to control hemorrhage may be unrewarding; alternative therapies such as plasma transfusions or coagulation factor concentrates should be investigated.
未成熟的环纹耳孔线虫动脉炎导致野生北方海象（Mirounga angustirostris）出现出血素质，这归因于肺线虫环纹耳孔线虫幼虫的异常迁移。临床症状通常不具特异性，包括嗜睡、厌食和眼睑痉挛，但可在发病后72小时内发展为自发性明显出血和死亡。先前发表的病例报告描述了凝血功能障碍，凝血酶原时间（PT）和活化部分凝血活酶时间（APTT）延长，血小板计数正常至升高，抗凝血酶浓度正常，纤维蛋白原降解产物浓度低。曾有人提出弥散性血管内凝血是出血的原因，但这与一些报道的临床病理变化不一致。
本研究的目的是比较健康和感染耳孔线虫的海象的血浆凝血和纤维蛋白溶解情况，以确定潜在的治疗方法。我们假设高纤维蛋白溶解是这些病例出血的原因。
从一家野生动物康复医院收集3至4个月大的北方海象的枸橼酸盐血浆样本。抽样群体包括25只健康的、即将放归的海豹和32只临床患病的海豹，这些海豹被诊断为疑似耳孔线虫动脉炎。其中21只海豹在尸检时确诊有耳孔线虫感染。进行标准凝血试验和血浆血栓弹力图检查以全面评估凝血和纤维蛋白溶解情况。
与健康对照组相比，确诊感染耳孔线虫的北方海象存在低凝和低纤维蛋白溶解状态。
结果与弥散性血管内凝血最为一致。使用抗纤维蛋白溶解药物控制出血可能无效；应研究替代疗法，如输血或凝血因子浓缩物。
