当前兔病及管理中亟待注意的问题

(一)兔瘟切勿大意 2000年我国大部分地区小规模养殖户中发生了亚急性兔瘟,兔瘟已由最急性向亚急性迅速转变,这缘于多年的疫苗防治效果。但是由于一些养殖户的侥幸心理和麻痹大意,还有对疫苗注射情况的不了解,造成兔瘟发病趋势恶化。笔者曾解剖了几十起因兔瘟死亡的病例,结果发现亚急性兔瘟症状极其明     

正确应用兔瘟疫苗

随着养兔生产的发展,各种防疫体系相继建立且逐步完善,主要传染病如兔瘟、兔出败、兔魏氏梭菌等均已有了一定的预防措施。在疫苗制备上不断改进,从单苗到联苗,既减少劳动力,也简化了手续,大大方便了生产,深受广大兔场和养兔户的欢迎。但是,在疫苗的应用中也常出现一些问题,必须引起重视。如使用兔瘟与巴氏杆菌二联苗后,幼兔仍出现兔瘟病而死亡,不得不对发生兔瘟的病兔使用兔瘟血清及兔瘟疫苗进行紧急接种。发生上述情况的原因,主要是各地收购兔毛的商贩较多,造成兔瘟病毒传播,一旦强毒带进兔场,就会导致免疫失败和兔瘟病暴发。常用的兔瘟疫苗有兔瘟油乳化苗、兔瘟甲醛灭活苗。油乳化苗安全可靠,注射后局部无肿块和炎症,免疫期可维持4～6个月。从抗体消长动态看,油乳化亩优于甲醛苗。根据我们经验。正确应用兔瘟疫苗,主要应注意以下几点:(1)先对兔群进行兔瘟单苗预防注射,然后在可能的情况下再考虑是否使用其他联苗。应用兔瘟单苗一年应不少于2次。     

浅谈当前兔瘟流行特点与预防措施

兔瘟是由兔瘟病毒引起的一种急性、烈性、败血性、致死性以及高度接触性传染病,是危害养兔业的主要疾病之一。本文综述了兔瘟的流行特点、临床症状、病理变化,并就兔瘟免疫失败的原因进行讨论,提出针对性的预防措施。     

肉兔几种常见病的防治

1兔瘟 兔瘟是在肉兔养殖中较为常见的疾病。兔瘟有高死亡率,传染速度快,发病快的特点。肉兔鼻孔流血,肛门有淡黄色胶样液体排出,所感染肉兔迅速死亡。若经过对感染兔瘟且死亡的肉兔尸检可见其肾、肺、心、肝、小肠均有多处出血点。对于兔瘟目前没有有效的治疗措施,但通过借助半年一次的接种疫苗可有效预防兔瘟的发生。     

兔瘟蜂胶组织灭活苗的研制及免疫效果观察

采用人工感染兔瘟(兔病毒性出血症)病毒致死的兔的脏器(主要是肝)，制成10％的兔瘟组织灭活苗和10％的兔瘟蜂胶组织灭活苗。采用常规血凝抑制实验，初步分析比较了注射兔瘟组织灭活苗和兔瘟蜂胶组织灭活苗后兔体内抗体水平的消长情况。结果表明：兔瘟蜂胶组织灭活苗能明显提高抗体效价，增强免疫效果。     

开春时节常见兔病的防控技术

正开春时节正是家兔的繁殖旺季,乍暖还寒,雨雪天气多,兔瘟、传染性鼻炎、皮肤真菌病等易多发,给养兔生产带来了许多困难。要采取综合措施,加强防控。1兔瘟兔瘟又名兔病毒性出血症,是由兔出血性病毒引起的一种急性、烈性传染病,其来势凶猛、传播迅速,病期短,发病率和死亡率高,是危害养兔业的主要疾病之一。1.1流行特点本病一年四季均可发生,但以冬、春季发病多,炎热夏季发病较少。近年来,兔瘟发病趋于低龄化,死亡幼兔中40～60日龄兔占很大比例,改变了以往兔瘟多     

一例兔瘟的诊治报告

兔瘟是养兔业危害极大疾病之一。介绍了一例兔瘟疾病的发病情况,临床表现,病理变化以及鉴别诊断和防治方法。为兔瘟的诊治提供参考。     

兔瘟及防治措施

兔瘟又称兔病毒性出血症,是兔出血症病毒引起的一种急性、高度传染性疾病,对养兔生产造成极大的危害。近年来,虽然各养兔单位和个人加大对兔瘟的防治措施,但仍有为数不少的兔场发生兔瘟,给     

非典型兔瘟（慢性兔瘟）简介

自1984年春在我国江苏无锡地区首次发现兔病毒性出血症（兔瘟）并分离到病毒以来，该病随后蔓延至全国及世界各养兔国家，至今已20余年。目前，兔瘟在我国已位列家兔最主要的传染病之首．人们对其的认识、研究正在逐步深入。兔瘟出现不久兔瘟组织疫苗即应运而生并沿用至今，其免疫效果确实可靠，对防制本病起到了关键作用。     

抗兔瘟精制卵黄抗体的研制

选用免疫原性好的兔瘟抗原加工成浓缩兔瘟灭活组织疫苗,按特定的免疫程序接种健康商品鸡群,通过血凝抑制试验检测免疫鸡群血清和卵黄的兔瘟抗体效价,适时收集高免卵黄,选用特定的抗体分离提纯工艺,研制对兔瘟有预防和治疗双重作用的精制卵黄抗体。经实验室生物学检验,本品使用无刺激,作用迅速,对兔瘟早期治愈率为80%,对兔瘟紧急预防有效率为100%。     

Fatal herpesvirus infection in commercial rabbits

Acute mortality occurred in two unrelated rabbitries. In the rabbits examined, an unidentified herpesvirus caused lesions that have not been reported previously in this species. The primary lesions were multifocal hemorrhagic dermatitis on the face and back, localized pneumonia, and severe splenic necrosis. Large eosinophilic, intranuclear inclusion bodies that were observed in tissue sections of skin, spleen, and lung were identified as herpes-like viral particles by electron microscopy, and herpesvirus was cultured on rabbit kidney cells. Intramuscular injection of tissue culture fluid containing virus resulted in mortality and severe illness in two seven-week-old domestic rabbits four and six days postinfection, respectively. The gross and microscopic lesions were reproduced and herpeslike viral inclusions were observed in skin lesions. Herpesvirus was recovered from lung, trachea, spleen, liver, and from the thigh muscle at the site of inoculation. The experimental infection also activated severe pasteurella septicemia. The herpesvirus isolate needs further characterization.     

多杀性巴氏杆菌病研究进展

多杀性巴氏杆菌(P.multocida)是引起多种畜禽巴氏杆菌病(pasteurellosis)的病原菌,主要引起动物发生出血性败血病或传染性肺炎。动物之间相互传染,人被动物咬伤可感染。畜禽巴氏杆菌病的防治主要使用多杀性巴氏杆菌疫苗.目前防制巴氏杆菌病的疫苗主要有强毒灭活菌苗、弱毒菌苗和亚单位疫苗,这些疫苗在一定程度上对巴氏杆菌病的防治起到了一定的作用,但由于多杀性巴氏杆菌的血清型多,免疫效果也不理想,有关巴氏杆菌病防治还有待进一步研究。本文就多杀性巴氏杆菌的毒力因子、免疫原等进行综合阐述。     

兔病毒性出血症病毒高免血清的制备与应用效果

以兔病毒性出血症病毒组织灭活疫苗免疫家兔，经五次免疫之后，抗体效价可达12log2以上，采集兔血清，以此治疗攻毒兔，结果大部分兔都存活，临床应用效果表明：以此血清治疗自然感染兔病毒性出血症病毒的发病兔，治愈率达80％以上。     

Viral diseases of the rabbit.

Viral disease in the rabbit is encountered infrequently by the clinical practitioner; however, several viral diseases were reported to occur in this species. Viral diseases that are described in the rabbit primarily may affect the integument, gastrointestinal tract or, central nervous system or maybe multi-systemic in nature. Rabbit viral diseases range from oral papillomatosis, with benign clinical signs, to rabbit hemorrhagic disease and myxomatosis, which may result in significant clinical disease and mortality. The wild rabbit may serve as a reservoir for disease transmission for many of these viral agents. In general, treatment of viral disease in the rabbit is supportive in nature.     

Passive immunization of Pacific herring against viral hemorrhagic septicemia

The plasma of Pacific herring Clupea pallasii that survived laboratory-induced viral hemorrhagic septicemia (VHS) epizootics contained humoral substances that, when injected into naive animals, conferred passive immunity against the disease. Among groups exposed to viral hemorrhagic septicemia virus (VHSV), injection of donor plasma from VHS survivors resulted in significantly greater survival (50%) and significantly lower tissue titers (1.5 x 10(5) plaque-forming units [PFU]/g) than the injection of plasma from VHSV-naive donors (6% survival; 3.7 x 10(6) PFU/g). Additionally, the magnitude of the protective immune response increased during the postexposure period; plasma that was collected from survivors at 123 d postexposure (931 degree-days) provided greater protection than plasma collected from survivors at 60 d postexposure (409 degree-days). These results provide proof of concept that the VHSV exposure history of Pacific herring populations can be determined post hoc; furthermore, the results can be used as the foundation for developing additional high-throughput diagnostic techniques that may be effective at quantifying herd immunity and forecasting the potential for future VHS epizootics in populations of wild Pacific herring.     

鼠疫F1和V保护性抗原免疫学研究进展

鼠疫是一种烈性人兽共患传染病,曾经导致历史上10多亿人死亡,目前在世界各地还均有流行。抗生素治疗一般对腺鼠疫有效,但难以治疗肺鼠疫,经常有抗生素治疗仍死亡的情况发生。灭活疫苗对肺鼠疫无效,减毒活疫苗存在毒力返强的安全隐患。F1和V亚单位疫苗在动物模型中对腺鼠疫和肺鼠疫均有效,已经用减毒沙门菌系统通过口服和鼻腔途径传递系统进行免疫研究。文章综述了鼠疫亚单位疫苗和减毒活载体疫苗抗原免疫学研究进展。     

DNA Vaccination of Rainbow Trout against Viral Hemorrhagic Septicemia Virus: A Dose–Response and Time–Course Study

Abstract

Viral hemorrhagic septicemia (VHS) in rainbow trout Oncorhynchus mykiss is caused by VHS virus (VHSV), which belongs to the rhabdovirus family. Among the different strategies for immunizing fish with a recombinant vaccine, genetic immunization has recently proven to be highly effective. To further investigate the potential for protecting fish against VHS by DNA vaccination, experiments were conducted to determine the amount of plasmid DNA needed for induction of protective immunity. The time to onset of immunity and the duration of protection following administration of a protective vaccine dose were also analyzed. The dose–response analysis revealed that significant protection of rainbow trout fingerlings was obtained following intramuscular injection of only 0.01 μg of plasmid DNA encoding the VHSV glycoprotein gene. In addition, higher doses of DNA induced immunity to a virus isolate serologically different from the isolate used for vaccine development. Following administration of 1 μg of a DNA vaccine, significant protection against VHS was observed in the fish as early as 8 d postvaccination. At 168 d postvaccination, the fish had increased in size by a factor of 10 and protection against a lethal dose of VHSV was still evident. The results confirm the great potential for DNA vaccination in inducing efficient immunoprophylaxis against viral diseases in aquacultured fish.     

兔病毒性出血症自然感染病例的解剖病理学观察

为了给兽医临床诊断兔瘟病提供病理学快速诊断依据,对一起非典型兔瘟(慢性兔瘟)病例的发病情况和解剖病理变化进行了详细观察和拍照,并通过对流行病学调查、临床症状、剖检病理变化、实验室微生物学检查和血清学检测等综合分析,确诊为兔瘟。观察到兔瘟病主要病理变化表现为心脏充血、心耳充血明显,心包积液,心内外膜有散在针尖大小出血点;喉头和气管黏膜充血和出血,气管内有泡沫状液体;肺脏水肿、出血;胸腺严重水肿、出血,有的肿大3～5倍,外观大理石样;肝脏稍肿大、土黄色、质地脆弱;脾脏肿大,呈紫黑色,边缘有锯齿状坏死;胃壁变薄,黏膜易脱落;结肠充气鼓胀,浆膜有出血点或出血斑;肠系膜淋巴结肿大、点状出血;肾脏水肿、土黄色、有出血点或出血斑;膀胱积尿、有出血点;母兔子宫水肿、出血等。本试验为兽医临床快速诊断兔瘟病提供参考资料。     

Sequential pathology after experimental infection with marine viral hemorrhagic septicemia virus isolates of low and high virulence in turbot (Scophthalmus maximus L)

Three marine viral hemorrhagic septicemia virus isolates were used to bath challenge turbot with the purpose of studying mortality and the pathology and antigen distribution over time. Two high-virulence isolates, 860/94, 4p168 and a low-virulence isolate 1p3 from a Baltic Sea herring were used. Organ samples were collected sequentially at 2, 4, 7, 10, 15, 20, 25, and 45 days postinfection. Specimens were processed for virology, histopathology, and immunohistochemistry. Organs during the early stages of infection (from 2 to 7 days) had virus isolation from all three groups only on day 7. Virus titer in kidney and heart sampled at day 25 was higher for the two virulent isolates compared with the low-virulence isolate. The viral distribution in situ of the two more virulent isolates from turbot (860/94) and herring (4p168) resembled viral hemorrhagic septicemia in rainbow trout with regard to the target organs. Early infection of endothelial cells in both kidney and heart was observed. Accumulated mean mortality was 41.5% for the turbot isolate 860/94, 48% for the herring isolate 4p168, and 3.5% for the herring isolate 1p3. This study revealed that the isolates from turbot (860/94) and herring (4p168) induced significantly higher mortality compared with the virus-free control and the herring isolate (1p3). The onset of mortality is markedly later in turbot compared with what is seen in rainbow trout.     

Influence of Temperature on the Efficacy of Homologous and Heterologous DNA Vaccines against Viral Hemorrhagic Septicemia in Pacific Herring

Abstract

Homologous and heterologous (genogroup Ia) DNA vaccines against viral hemorrhagic septicemia virus (genogroup IVa) conferred partial protection in Pacific Herring Clupea pallasii. Early protection at 2 weeks postvaccination (PV) was low and occurred only at an elevated temperature (12.6°C, 189 degree days), where the relative percent survival following viral exposure was similar for the two vaccines (IVa and Ia) and higher than that of negative controls at the same temperature. Late protection at 10 weeks PV was induced by both vaccines but was higher with the homologous vaccine at both 9.0°C and 12.6°C. Virus neutralization titers were detected among 55% of all vaccinated fish at 10 weeks PV. The results suggest that the immune response profile triggered by DNA vaccination of herring was similar to that reported for Rainbow Trout Oncorhynchus mykiss by Lorenzen and LaPatra in 2005, who found interferon responses in the early days PV and the transition to adaptive response later. However, the protective effect was far less prominent in herring, possibly reflecting different physiologies or adaptations of the two fish species.

Received August 1, 2016; accepted March 10, 2017 Published online July 11, 2017