边界病的研究进展

边界病（border disease,BD）是由边界病病毒（border disease virus,BDV）引起绵羊和山羊感染的一种传染性疾病,在世界范围内给畜牧业生产造成巨大的经济损失。该病临床表现为母羊生殖障碍,羔羊畸形、震颤、多毛等。BDV在绵羊、牛和猪的种间传播经常发生,给该病的诊断带来困难。目前,尚无有效的疫苗用于边界病的防控,因此,了解不同区域的边界病流行情况有助于防止其传播并优化控制措施。结合国内外近期研究报道,从病原学、流行病学、诊断措施等方面对边界病进行综述,以期为该病的防控工作提供参考。     

羔羊传染性脓疱病的诊治

羔羊传染性脓疱病俗称“羊口疮” ,是绵羊和山羊的一种病毒引起的传染病 ,在羔羊多为群发。其特征为口唇等处皮肤和黏膜形成丘疹、脓疱、溃疡和形成疣状厚痂。近几年来 ,由于香加乡出生的羔羊感染传染性脓疱病比较普遍。笔者对该病的预防和治疗积累了一些经验 ,现介绍如下。1　发病情况该病多发于出生 1～ 3月龄的羔羊 ,以山羊为多数 ,多以群体发病为主 ,而且传染速度极快。病初表现为不愿吃母乳 ,若一群羔羊中发现一例呈现该病症状后 ,则大多数羔羊已经感染。发病率为 15 1%(489 32 41) ,死亡率为 7 2 5 %(2 35 32 41)。2　临床症状病初…     

羊衣原体病综合防治措施

羊衣原体病是由鹦鹉热衣原体感染引起的山羊、绵羊共患的一种传染性疾病,该种疾病在人群中传播速度较慢,通常情况下不会表现出致病能力,常常呈现隐性经过。母羊感染该种疾病后,常常在妊娠后期出现流产,产下死胎和弱胎。在该种疾病流行期也可以看到部分羔羊出现关节炎、结膜炎等症状。笔者主要结合实际情况,就一起羊衣原体病的诊断和防治进行了分析。     

羊流行性肝炎的诊断与预防

羊流行性肝炎是绵羊病毒性传染病，牛也可感染发病。本病潜伏期短，绵羊最易感，山羊最钝感。绵羊、牛、山羊和骆驼发病后，常引起孕畜流产，仔畜死亡。自然感染是由多种蚊传播的，猴、家鼠和牛是自然疫源，候鸟参与其传播。健康羊，特别是羔羊与患病羊一同饲养时，可能发生感染，子宫内感染也已被证明，流产胎儿体内含有大量病毒。人类流行性肝炎常因接触病畜或病料而发生感染，传播途径主要是呼吸道，蚊虫叮咬在人类感染中占次要地位。     

羔羊肺炎的防治

羔羊肺炎由不同病原菌感染所引起,绵羊和山羊都可发生;母羊营养不良,泌乳量不足,羊舍卫生条件差,气温突变等都能诱发该病;病羊以呼吸道症状为主要表现,严重的可导致死亡;预防本病需加强羔羊的护理和保健,疾病流行季节或羊群中发现病例时可及时用药物控制;对致病菌敏感的抗生素可用于本病的治疗。     

浅谈小反刍兽疫

正小反刍兽疫是由副黏病毒科麻疹病毒属的小反刍兽疫病毒引起的在山羊和绵羊中流行的一种传染性疾病。近年来,该病的传播呈扩大趋势,严重威胁着畜牧业产品的生产及安全。1易感动物群体该病的易感动物主要是山羊和绵羊。该病毒对山羊和绵羊的影响比较复杂,有的毒株会使绵羊表现出较高的死亡率,山羊不易感或者仅有轻微症状。有的毒株则会产生相反的效果。研究表明,猪和牛易感但不表现疾病症状,也不会传播疾病。     

羊肠毒血症的防控

羊肠毒血症是由D型魏氏梭菌感染所引起,多发于羔羊,临床以散发为主,绵羊和山羊都能感染,消化道是该病的最主要传播途径。根据临床发病缓急可分为最急性型和急性型两种,病羊主要表现全身症状,死亡率高;预防本病需提升羊场管理水平,定期使用微生态制剂;治疗本病时建议采用对因治疗和对症治疗相结合的方案。     

羊支原体肺炎的诊断及防治

正羊支原体肺炎是广泛流行于山羊、绵羊中的疾病,严重危害羊的生长、生产性能。该病是由革兰氏阴性菌丝状支原体山羊亚种、绵羊肺炎支原体、山羊支原体山羊亚种等支原体引发的高度接触性传染病,以急性纤维素性肺炎和胸膜炎为主。临床特征主要表现为体温高、咳嗽、呼吸急促困难,若是怀孕母羊感染该病,将导致母羊流产。羊肺炎流行于我国多个省份,特别是对羔羊的影响最大,病羊死亡率可达35%~50%,严重危害一些种羊生产基地,从而成为一种限制羊养     

边界病

边界病段宏安（中国连云港动植物检疫局，江苏２２２０４２边界病（ＢｏｒｄｅｒＢｉｓｅａｓｅ，ＢＤ）是由边界病病毒引起的，主要侵害绵羊的一种传染病，以新生羔羊体表出现茸毛状胎毛（ｈａｉｒｙｂｉｒｔｈｃｏａｔ）、持续节律性震颤以及中枢神经髓鞘缺失或异常为特...     

引起羊黄疸的几种传染病的临床鉴别

1传染性地方流行性肝炎 本病病毒为核糖核酸病毒,有很广的脊椎动物寄生谱,绵羊发病最严重,其次是山羊。多种蚊子可传播该病毒,所有年龄的绵羊均可感染,羔羊最严重。发病率在羊群中高达100%,1周龄以内的羔羊死亡率高达95%。最急性病例突然倒地死亡。急性病例潜伏期非常短,发热,脉搏加快,步态不稳,呕吐,流粘液性鼻液,出血性腹泻和可视黏膜有血斑或血点,在24-72小时内死亡。亚急性病例发生在成年绵羊,病羊发热并伴随厌食和虚弱,黄疸是主要症状,还有一些羊出现呕吐和腹痛的症状。孕羊流产为绵羊患病的唯一特征,山羊与绵羊症状相似,没有绵羊严重。可用酶联免疫吸附测定试验和反向被动凝集试验快速检查血样中的病毒抗原。     

羊病毒性关节炎-脑炎诊断与防治

羊病毒性关节炎-脑炎是由反转录病毒科慢病毒属山羊关节脑炎病毒引发的一种病毒性传染性疾病。临床上患病羊所出现的持续性的病症是急性脑脊髓炎,成年羊表现为关节炎、乳腺炎、慢性进行性肺炎和脑炎。病毒危害的羊群终身携带病毒,成为养殖场的主要传染源。由于该类疾病没有特效药物,再加上传染源的存在,经常会造成羊群反复流行该类疾病,最终引发死亡,对整个群体造成的威胁极大。为缩小经济损失、提高牲畜生产性能,该文探讨羊病毒性关节炎-脑炎的诊断与防治过程。     

A serological survey of Akabane virus infection in cattle and sheep in northwest China

Purpose

Akabane disease characterized mainly by fetal damage is a ruminant disease caused by insect-transmitted Akabane virus infection.

Methods

We investigated Akabane disease using serum neutralization tests in 446 blood samples collected from 187 cattle and 259 sheep of Xinjiang province, northwest China.

Results

(1) The overall prevalence rate of neutralizing antibody was 19.06?% (85/446), (2) the prevalence rates of Akabane disease in cattle and sheep were 20.32?% (38/187) and 18.15?% (47/259), respectively, (3) the disease prevalence rates were not significantly different between cattle and sheep, but significantly different among samples collected from different sampling months, (4) the disease was most prevalent in July when mosquitoes and culicoides were most active, and (5) the disease prevalence rates were significantly different between individuals with abortion experience and without abortion experience (P?<?0.05), suggesting that Akabane virus infection may significantly increase abortion risk in cattle and sheep.

Conclusions

To our knowledge, this is the first report confirming that Akabane virus infection is common in cattle and sheep of Xinjiang province, northwest China and providing useful epidemiological information for cattle and sheep abortion prevention and control.     

Border disease of sheep: the disease in the newborn, adolescent and adult.

Border disease (BD) is a condition of newborn sheep that results from congenital infection by a non-cytopathic pestivirus occurring during the first half of gestation. The expression of the virus is largely determined by the age of the fetus at the time of infection, producing four distinct disease syndromes: (1) early embryonic death, (2) abortion and stillbirth, (3) birth of lambs with malformations, and (4) birth of small, weak lambs, lacking characteristic clinical signs, but bearing features of immunosuppression. The effects of the virus infection during the developmental stages of the fetus are most apparent as distinctive clinical signs at the time of birth but a state of specific immuno-tolerance with associated virus persistence remains for the lifetime of the sheep. Although the clinical signs disappear with time, some effects of virus persistence may continue into adolescence and often into adulthood. Characteristic lesions are found in the nervous, endocrine, skeletal and integumentary, and immune systems.     

绵羊种布鲁菌致病机制与防控研究进展

布鲁菌病(Brucellosis)是一种高度流行的人畜共患传染病,可造成巨大的经济损失,严重制约了当今畜牧业的发展并对人类健康构成了严重威胁。绵羊种布鲁菌病是由绵羊种布鲁菌(Brucella ovis,B.ovis)引起的一种以绵羊生殖系统功能障碍和怀孕绵羊流产为特征的慢性传染性疾病。目前,对于绵羊种布鲁菌的胞内寄生机制和感染机制尚不清楚,现将从病原学、流行病学、致病机制和疾病防控等方面对绵羊种布鲁菌病的研究进展进行概述,为后期挖掘绵羊种布鲁菌的致病机理和与其相关的研究奠定一定的理论基础。     

羊口疮病预防与专业治疗方案

羊口疮病又被称为羊传染性脓疱病,是由羊口疮病毒感染引发的一种高度接触性急性传染性疾病。该病具有传播速度、传播范围广、发病率高的特点,虽然造成的死亡率降低,但是会严重影响羊的正常产生、正常休息,使羊群生长发育不良,身体逐渐消瘦,如果继发感染多种细菌性疾病、病毒性疾病,会加重病情,表现出复杂的临床症状,给疾病的诊断工作带来很大难度。养殖户在发展羊养殖中如果没有做好科学管理,饲料中存在杂质或者饲料坚硬,造成羊口腔出现损伤,给传染性脓疱病的发生流行提供条件。发生流行后如果不能做好针对有效的诊断,易造成病原的扩散蔓延,带来严重损失。该文主要论述羊口疮病的预防和治疗。     

Age-specific seroprevalence of Border disease virus and presence of persistently infected sheep in Basque dairy-sheep flocks

Using p125/p80 antibody and antigen-ELISA tests, age-specific seroprevalence and presence of persistently infected (PI) sheep were investigated in six commercial latxa dairy-flocks, housed for variable periods. The flocks all had a recent history of Border disease (BD). Every flock included seropositive sheep and seven 0.5-3-year-old PI sheep were detected in two of four flocks tested. Age-specific antibody patterns differed according to the presence or absence of PI sheep in the flock. In flocks free of PI sheep, seroprevalence was 6-13% in 1-year-old sheep and 42-93% in older sheep. In contrast, seroprevalence was 67-99% in sheep raised with PI sheep for at least 1 year and 29-33% in replacement 0.5-0.6-year-old sheep (including a PI sheep) indicating that Border disease virus (BDV) transmission in Basque dairy-flocks can be relatively slow. Moderate seroprevalence in young replacement sheep should not discourage further testing to detect PI sheep, and our results highlight the risk of failing to achieve "natural vaccination" prior to pregnancy by mixing PI sheep with BDV-unexposed ewes.     

Persistence of FDMV and its effects on disease control strategies

It is well-known that foot-and-mouth disease virus (FMDV) causes a persistent infection, lasting for more than 28 days, in cattle, sheep, goat as well as some other ruminant species, but not in pigs. Although convincing evidence for virus transmission is missing, these carrier animals have to be considered as a potential risk of infection. Some aspects of FMDV persistence are presented and discussed with regard to disease control strategies.     

Diagnosis of ovine chlamydial abortions by PCR-RFLP performed on vaginal swabs

Ovine enzootic abortion is an infectious and contagious disease clinically characterized by abortion and weak neonates, affecting sheep and goats. The etiological agent is Chlamydophila (C.) abortus, which is considered one of the most common animal pathogens of small ruminants; it has important economic implications and represents a significant zoonotic risk. Clinical diagnosis is often difficult because the clinical signs and the pathological lesions are not specific for C. abortus infection, in fact they can also be observed as a result of infections with other abortifacient agents. Moreover, the involvement of the laboratory is necessary to perform the definitive diagnosis. One hundred and seventeen vaginal swabs from sheep with clinical signs related to chlamydial infection were examined by a PCR-RFLP assay that demonstrated high specifity and sensitivity. Six samples were positive for C. abortus. Vaginal swabs are easy to handle and allow to deal with biohazardous material in safety conditions.     

影响持续感染的因素研究进展

持续感染是指病原体在宿主体内持续存在而不被清除的状态,其潜伏期长达数月至数年甚至终生,但不引起症状,病原体不一定持续增殖。不同病原体所致持续感染的定义不同,如口蹄疫病毒(FMDV)引起的持续感染被定义为动物感染28d后仍然携带活的病毒。持续感染是造成免疫失败、肿瘤形成或药物敏感性下降的重要原因。存在持续感染的宿主是重要的传染源,还是病原体发生变异的来源,但因无症状常被忽视。充分了解持续感染的形成机理及持续感染状态中宿主与病原体之间的相互作用,有助于寻找诊断、治疗和预防感染性疾病的最佳方法。论文从病原体和宿主因素两个方面阐述了持续感染的形成机理。