Mazepa Allison Wistrand, Kidd Linda Benjamin, Young Karen M, Trepanier Lauren A
Departments of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, Wisconsin 53706-1102, USA.
J Am Anim Hosp Assoc. 2010 Nov-Dec;46(6):405-12. doi: 10.5326/0460405.
Anaplasma (A.) phagocytophilum, the etiological agent of canine granulocytic anaplasmosis, is capable of inciting moderate to severe clinical disease in a variety of mammals and is endemic in the upper midwest. The purpose of this study was fourfold: to describe the range of clinical signs in dogs seropositive to A. phagocytophilum; to examine the prevalence of immune-mediated hemolytic anemia (IMHA) in this population; to evaluate whether specific clinical signs were associated with coexposure to Borrelia (B.) burgdorferi in actively infected dogs; and to determine whether clinical response to doxycycline was complete in treated dogs. Medical records of dogs seropositive for A. phagocytophilum were reviewed retrospectively. Peripheral blood smears were also reviewed retrospectively for granulocytic Anaplasma morulae. Lethargy (81%), inappetence (58%), and lameness (50%) were the most common clinical signs, followed by fever (46%). Thrombocytopenia was the most common laboratory abnormality, and IMHA was diagnosed in three dogs. Dogs that were thrombocytopenic and had antibodies to both A. phagocytophilum and B. burgdorferi had a median platelet count of 51,000/μL (range 20,000 to 171,000/μL), which was significantly lower than the count in dogs with antibodies only to A. phagocytophilum (P=0.04). Some dogs had an apparent relapse of clinical signs after an appropriate course of doxycycline. Testing for A. phagocytophilum by polymerase chain reaction, serum antibody assays, and/or blood smear evaluation should be considered in dogs with IMHA, cough, or epistaxis and that reside in A. phagocytophilum-endemic areas. If moderate to severe thrombocytopenia is present, testing for concurrent B. burgdorferi infection may be warranted.
嗜吞噬细胞无形体（A. phagocytophilum）是犬粒细胞无形体病的病原体，能够在多种哺乳动物中引发中度至重度临床疾病，在美国中西部上半区呈地方性流行。本研究的目的有四个：描述嗜吞噬细胞无形体血清学阳性犬的临床症状范围；检查该群体中免疫介导的溶血性贫血（IMHA）的患病率；评估在活跃感染的犬中，特定临床症状是否与同时感染伯氏疏螺旋体（B. burgdorferi）有关；确定治疗犬对强力霉素的临床反应是否完全。对嗜吞噬细胞无形体血清学阳性犬的病历进行了回顾性分析。外周血涂片也进行了回顾性分析，以查找粒细胞无形体桑葚体。嗜睡（81%）、食欲不振（58%）和跛行（50%）是最常见的临床症状，其次是发热（46%）。血小板减少是最常见的实验室异常，三只犬被诊断为IMHA。血小板减少且同时具有嗜吞噬细胞无形体和伯氏疏螺旋体抗体的犬，其血小板计数中位数为51,000/μL（范围为20,000至171,000/μL），显著低于仅具有嗜吞噬细胞无形体抗体的犬（P = 0.04）。一些犬在接受适当疗程的强力霉素治疗后，临床症状明显复发。对于患有IMHA、咳嗽或鼻出血且居住在嗜吞噬细胞无形体流行地区的犬，应考虑通过聚合酶链反应、血清抗体检测和/或血涂片评估来检测嗜吞噬细胞无形体。如果存在中度至重度血小板减少，可能有必要检测是否同时感染伯氏疏螺旋体。
