James Frances M, Engiles Julie B, Beech Jill
Department of Clinical Studies, University of Pennsylvania, PA 19348, USA.
J Am Vet Med Assoc. 2010 Nov 15;237(10):1180-5. doi: 10.2460/javma.237.10.1180.
A 12-year-old Thoroughbred was examined because of signs of depression, neck stiffness, and poor performance.
Physical examination revealed that the horse was dull, appeared depressed, was reluctant to raise its neck and head above a horizontal plane, and had a temperature of 38.5°C (101.3°F). No radiographic or scintigraphic abnormalities of the neck were found; however, high plasma fibrinogen concentration and relative lymphopenia were identified and the horse was seropositive for antibodies against Borrelia burgdorferi. Analysis of CSF revealed neutrophilic inflammation, and results of a PCR assay of CSF for B burgdorferi DNA were positive. Immunologic testing revealed severe B-cell lymphopenia and a low serum IgM concentration consistent with common variable immunodeficiency.
The horse responded well to do×ycycline treatment (10 mg/kg [4.5 mg/lb], PO, q 12 h for 60 days) and returned to normal exercise. However, 60 days after treatment was discontinued, the horse again developed a stiff neck and rapidly progressive neurologic deficits, including severe ataxia and vestibular deficits. The horse's condition deteriorated rapidly despite IV oxytetracycline treatment, and the horse was euthanatized. Postmortem examination revealed leptomeningitis, lymphohistiocytic leptomeningeal vasculitis, cranial neuritis, and peripheral radiculoneuritis with Wallerian degeneration; findings were consistent with a diagnosis of neuroborreliosis.
Nervous system infection with B burgdorferi should be considered in horses with evidence of meningitis and high or equivocal serum anti-B burgdorferi antibody titers. Evaluation of immune function is recommended in adult horses evaluated because of primary bacterial meningitis.
一匹12岁的纯种马因出现抑郁、颈部僵硬和表现不佳的症状而接受检查。
体格检查发现这匹马神情迟钝、显得抑郁，不愿将颈部和头部抬高至水平面以上，体温为38.5°C（101.3°F）。未发现颈部有放射学或闪烁扫描异常；然而，检测到血浆纤维蛋白原浓度升高和相对淋巴细胞减少，且该马抗伯氏疏螺旋体抗体血清学检测呈阳性。脑脊液分析显示有嗜中性粒细胞炎症，脑脊液伯氏疏螺旋体DNA的聚合酶链反应检测结果为阳性。免疫检测显示严重的B细胞淋巴细胞减少和血清IgM浓度低，符合常见可变免疫缺陷。
这匹马对强力霉素治疗反应良好（10毫克/千克[4.5毫克/磅]，口服，每12小时一次，持续60天），并恢复了正常运动。然而，停药60天后，这匹马再次出现颈部僵硬和快速进展的神经功能缺损，包括严重共济失调和前庭功能缺损。尽管静脉注射了土霉素治疗，但马的病情仍迅速恶化，最终实施了安乐死。尸检发现有软脑膜炎、淋巴细胞组织细胞性软脑膜血管炎、颅神经炎和伴有华勒变性的周围神经根神经炎；这些发现符合神经型莱姆病的诊断。
对于有脑膜炎证据且血清抗伯氏疏螺旋体抗体滴度高或不确定的马匹，应考虑伯氏疏螺旋体感染神经系统。对于因原发性细菌性脑膜炎接受评估的成年马匹，建议评估其免疫功能。
