Differential diagnosis of dog hookworms based on PCR-RFLP from the ITS region of their rDNA

Species of Ancylostoma infecting dogs and sometimes humans are sympatric in many parts of the world. The establishment of a specific molecular diagnostic tool is important, not only to refine information for epidemiological studies, but also to evaluate the efficacy of vaccine programmes and assist in the development of specific drug treatments. The ITS region from 20 specimens of A. braziliense, collected from three separate geographical areas of Brazil, and from 10 specimens of A. caninum, collected from the same area in Brazil were sequenced and analyzed. Alignment of sequences showed that this gene is highly conserved. The intraspecific polymorphism for both species was less then 1%, whereas the interspecific polymorphism was 6.2, 7.3 and 9.4% between A. ceylanicum and A. braziliense; A. caninum and A. ceylanicum and A. ceylanicum and A. braziliense, respectively. Among the three species it was 12.3%. This revealed the ITS region as highly conserved and consequently a good molecular marker for diagnostic studies. In this work, four restriction enzymes were used in a PCR-RFLP using the ITS region of rDNA, to establish a differential diagnosis which discriminates between three Ancylostoma species, A. braziliense, A. caninum and A. ceylanicum. The best pattern was given by the HinfI enzyme, which produced different fragment sizes for each of the three species. Furthermore, the diagnostic tool differentiates DNA extracted directly from faeces of Ancylostoma-infected dogs.     

米尔贝肟片治疗犬弓蛔虫病与钩虫病的疗效观察

为了观察米尔贝肟片对犬弓蛔虫和钩虫驱虫效果,采用人工感染方式,对犬弓蛔虫和钩虫的动物模型进行疗效研究。结果表明,单次口服0.5 mg/kg米尔贝肟片对犬弓蛔虫和犬钩虫的虫卵减少率、驱虫有效率和治愈率均可达到100%。说明米尔贝肟片在治疗犬弓蛔虫和钩虫时具有剂量小、疗效高、作用快、副反应轻等特点,在临床治疗方面有十分广阔的应用前景。     

用犬贾第虫包囊人工感染幼犬后排虫规律研究

用大量犬贾第虫包囊人工感染幼犬后进行粪便检测,结果表明其排虫呈周期性,接虫后第8天检测到贾第虫包囊。接虫后第18天出现第一个排虫高峰,高峰期持续1～2 d。高峰期过后2～3 d再次出现一个高峰期,但高峰期持续的时间都不超过2 d。     

罗杜杂交仔犬与杜罗杂交仔犬生长性能的对比研究

利用罗威纳犬与杜伯文犬不同父母本杂交所产的仔犬,测量罗杜杂交仔犬与杜罗杂交仔犬的体重、体长、体高的生长性能。结果表明,罗杜杂交仔犬与杜罗杂交仔犬的体重、体高与体长都是随着年龄的增长而增长,但2个品种仔犬的生长性能差异都不显著,且全都与母本的体重、体高、体长增长趋势一样。     

Neospora caninum antibodies in commercial fetal bovine serum

The protozoan parasite Neospora caninum is a major cause of abortion in cattle throughout the world. In the process of propagating Neospora in vitro and producing specific antibodies for development of diagnostic assays in the food supply, our laboratory identified the presence of bovine antibodies to N. caninum in fetal bovine sera. The sera were produced commercially and preferentially recommended for tissue culture use and monoclonal antibody production. Seventeen different fetal bovine serum samples of different grades and from four different companies were examined for the presence of total IgG, IgG₁, IgG₂, and IgM specific for N. caninum. All of the tested serum samples recognized N. caninum specific bands on Western blot. Low IgG serum also recognized these antigens but with lower intensity. Antibody response was also evaluated using a commercially available ELISA kit for N. caninum.     

猪繁殖与呼吸综合征病毒垂直传播及其危害研究进展

猪繁殖与呼吸综合征病毒(PRRSV)感染引起的繁殖障碍在妊娠早期表现为母猪受胎率低、不规律返情及孕早期流产;怀孕后半期流产、早产,产死胎、木乃伊胎及弱仔等。先天感染的仔猪抵抗继发感染的能力低,可持续排毒并感染周围的阴性动物。PRRSV穿过胎盘屏障感染胎儿很可能是经巨噬细胞/单核细胞介导的,并在母胎界面造成病理损伤,病毒在胎儿着床点的复制可能是导致胎儿死亡和母猪流产的原因。预防PRRSV垂直传播必须控制母猪感染PRRSV,缩短已感染母猪的病毒血症持续时间,此外,通过生物安全、限制猪群流动和严格的消毒措施控制水平传播,通过疫苗免疫和药物保健消除易感动物。作者概述了妊娠各阶段母猪感染PRRSV发生垂直传播的情况及其后续的繁殖障碍。     

Models for experimental infection of dogs fed with tissue from fetuses and neonatal cattle naturally infected with Neospora caninum

Three models were designed to investigate the development and enteroepithelial phase of Neospora caninum in dogs, and to induce oocyst production by the parasite. In the first model, three dogs were fed raw fetal bovine tissue on two occasions. The bovine fetal tissue had been stored at 4 °C for 14 days and 16 days, respectively, and had tested positive for neosporosis using histopathology and immunohistochemistry. In the second model, nine dogs from the beginning of the experiment until euthanasia were fed portions of tissue from bovine fetuses that been stored at 4 °C for between 1 and 2 days. Three fetuses had tested positive for neosporosis using histopathology and immunohistochemistry. In the third model, three dogs were fed pieces of raw tissue from two neonatal calves that had not received colostrum, and which had tested positive for antibodies against N. caninum. The brains of these calves were positive for neosporosis by histopathology and immunohistochemistry. In all three models, none of the dogs excreted oocysts of N. caninum, developed intestinal parasites or seroconverted.     

警犬繁育中幼犬的淘汰原因分析

作者对某大型警犬繁殖基地2000～2007年2284只仔幼犬的培训情况及淘汰原因进行了分析。结果表明,2月龄仔犬的合格率为99.12%,2～6月龄幼犬的投训率、淘汰率和死亡率分别为87.40%、9.16%和3.44%。幼犬淘汰的最主要原因是不衔取或衔取欲低,占60.11%,其次是胆小,占16.85%。提示育种和幼犬培训应以提高犬的衔取欲和胆量为重点。     

Absence of vertical transmission of Helicobacter pylori in an experimental murine model

Helicobacter pylori (H. pylori) infection is acquired mainly in early childhood but the precise transmission routes are unclear. This study examined the maternal H. pylori infection status in order to determine the potential of perinatal transmission. These issues were investigated using an experimental murine model, the Mongolian gerbil, which has been reported to be the most suitable laboratory animal model for studying H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into two groups. The stomachs of the mother and litters were isolated and assessed for the transmission of H. pylori at the prenatal period (2 weeks after pregnancy) and at the parturition day. The bacterial culture, polymerase chain reaction (PCR) and rapid urease test were used to examine the presence of the transmitted H. pylori. There was no H. pylori observed in any of the fetuses during pregnancy and in the litters at parturition. This suggests that vertical infection during the prenatal period or delivery procedure is unlikely to be route of mother-to-child transmission of a H. pylori infection.     

Application of a temporary palatal prosthesis in a puppy suffering from cleft palate

A 3-month-old Schnauzer was presented with congenital defects of the secondary palate. On the clinical examination, coughing, sneezing, drainage of nasal discharge from the external nares and poor growth were found. Vital signs and results of blood examination were within normal ranges. Thoracic radiography revealed mild pneumonia in the right lung lobes. In a puppy suffering from cleft palates, a palatal prosthesis was applied to the hard palate in order to protect the surgical wound, because a routine surgery was not successful. A palatal prosthesis was applied and held in place using the instant glue and plastic bands to protect the surgical wound following the third repeated surgery. Although a small oronasal fistula still remained, there was no functional defect. This prosthesis was easy to apply and helpful to protect the surgical wound. In addition, this implant could be placed or adjusted without or sedation/anesthesia.     

浅谈仔犬警用行为研究中的标记技术

本文介绍了动物标记技术在仔犬警用行为研究中的应用。动物行为研究中的标记技术大致可分为：自然标记法;暂时标记法;半永久标记法;永久标记法。这些技术已用于多种动物行为研究之中,对于仔犬来说因其特殊的社群行为及心理生理结构,在观测其警用行为时,采用自然标记法和暂时标记法来标记仔犬,不仅方便而且效果也很显著。     

新一代驱虫抗生素—莫西菌素

莫西菌素同伊维菌素一样 ,是一种目前广泛用于兽医临床的广谱、高效、新型大环内酯类驱虫抗生素 ,是美贝霉素家族中的一员。由于其独特的理化性质 ,在国外 ,已被广泛用于治疗奶牛、猪等动物体内外寄生虫病。文章对莫西菌素的理化特性、作用机制、药动学、制剂、药效、耐药性、毒性、残留等进行了较详细地综述 ,同时也介绍了减少耐药性产生的一些方法 ,为该药能在国内应用提供第一手资料 ,以求为兽医临床用药提供参考     

鸡白痢沙门氏菌的垂直传播

本文旨在探讨鸡白痢沙门氏菌的垂直传播。结果发现,遏制细菌转播要做好以下几点：1．搞好清洁卫生和消毒;2．反复剔除带菌鸡;3．注意饲料中的沙门氏菌。     

牛、羊奶中莫昔克丁残留高效液相色谱荧光检测方法的建立

建立了适用于牛、羊奶样品中莫昔克丁残留的高效液相色谱荧光检测方法。以乙腈为提取液,C18固相萃取柱净化,并用N-甲基咪唑-乙腈(1+1,V/V)和三氟乙酸酐-乙腈(1+2,V/V)进行衍生化。乙腈+水(90+10,V/V)为流动相,荧光法定量。经测定,该方法对牛、羊奶中莫昔克丁的检测限为2 μg/kg,定量限为5 μg/kg。空白牛、羊奶中标准品莫昔克丁添加量分别为5、20、40和80 μg/kg时,牛奶中莫昔克丁平均回收率范围为75.5%～110%,其批内变异系数小于738%,批间变异系数小于7.87%;羊奶中莫昔克丁平均回收率范围为77.5%～95.6%,其批内变异系数小于5.06%,批间变异系数小于5.92%。该方法准确性强、灵敏度高,适用于牛、羊奶中莫昔克丁的快速检测。     

Assessing resistance of ivermectin and moxidectin against nematodes in cattle naturally infected using three different methodologies

The objective of this study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) and the faecal egg count efficacy test (FECET) to assess the resistance status of ivermectin (630 μg/kg) and moxidectin (200 μg/kg), using the controlled efficacy test as a reference, and whether the results of the EPG are equivalent to the efficacy results from the parasitological necropsies. Two experiments were conducted. The results demonstrate that it was not possible to demonstrate that the EPG values were equivalent with the ivermectin and moxidectin efficacy obtained by parasitological necropsies, mainly if the phenomenon of parasites resistance is not advanced in a determined field population. Maybe the FECET technique would be possibly better than the FECRT. The high anthelmintic efficacy of 200 μg/kg moxidectin, in naturally infected cattle, against field population of nematodes that are resistant to 630 μg/kg ivermectin, was observed in this study.