Allison Robin W, Yeagley Todd J, Levis Kristina, Reichard Mason V
Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Vet Clin Pathol. 2011 Sep;40(3):345-50. doi: 10.1111/j.1939-165X.2011.00332.x. Epub 2011 Jul 26.
A 5-month-old intact male Boerboel dog, imported from South Africa 1 week previously, was presented to a Texas veterinarian for lethargy, anorexia, and labored breathing. The dog was febrile, anemic, leukopenic, thrombocytopenic, and slightly azotemic. Results of the IDEXX SNAP-4Dx enzyme immunoassay were negative for Dirofilaria immitis antigen and antibodies against Ehrlichia canis, Borrelia burgdorferi, and Anaplasma phagocytophilum. An EDTA blood sample analyzed at Oklahoma State University Center for Veterinary Health Sciences revealed nonregenerative anemia, neutropenia, and large protozoal piroplasms in 0.7% of the RBCs. Piroplasms were 2-5μm long and varied in shape from round to oval to piriform; extracellular merozoites were also observed. Nested PCR was performed on DNA extracted from blood using primers that amplify the 18s rRNA gene from all known Babesia species, and the product was sequenced. Basic Local Alignment Search Tool analysis of the 437 base sequence revealed 99-100% similarity to Babesia canis rossi, 92-93% similarity to Babesia canis canis, and 92% similarity to Babesia canis vogeli. The dog responded well to treatment with imidocarb. PCR analysis of a second blood sample 2 weeks later was negative for Babesia spp. DNA. This case represents the first diagnosis of B. canis rossi infection in the United States.
一只5个月大的未绝育雄性布尔博尔犬，一周前从南非进口，因嗜睡、厌食和呼吸困难被送到德克萨斯州的一位兽医处。这只狗发热、贫血、白细胞减少、血小板减少且有轻微氮质血症。IDEXX SNAP - 4Dx酶免疫分析结果显示，犬恶丝虫抗原以及针对犬埃立克体、伯氏疏螺旋体和嗜吞噬细胞无形体的抗体均为阴性。在俄克拉荷马州立大学兽医健康科学中心对一份乙二胺四乙酸（EDTA）血样进行分析，结果显示为非再生性贫血、中性粒细胞减少，且在0.7%的红细胞中发现大型原生动物梨形虫。梨形虫长2 - 5μm，形状从圆形到椭圆形再到梨形不等；还观察到细胞外裂殖子。使用能扩增所有已知巴贝斯虫属物种18s rRNA基因的引物，对从血液中提取的DNA进行巢式聚合酶链反应（PCR），并对产物进行测序。对437个碱基序列进行基本局部比对搜索工具（Basic Local Alignment Search Tool）分析发现，其与犬巴贝斯虫罗斯亚种的相似度为99 - 100%，与犬巴贝斯虫犬亚种的相似度为92 - 93%，与犬巴贝斯虫沃氏亚种的相似度为92%。这只狗对咪唑苯脲治疗反应良好。两周后对第二份血样进行PCR分析，结果显示巴贝斯虫属DNA呈阴性。该病例代表了美国首例犬巴贝斯虫罗斯亚种感染的诊断。
