红鼓鱼鱼苗流行爆发性病病因探讨

2000年夏秋季，福建罗源湾网箱养殖的红鼓鱼鱼苗流行爆发性疾病，死亡率高达40%～90%。使用抗生素治疗效果甚微。显微镜检查基本无寄生虫感染。电镜检查发现病鱼脾脏内大量寄生一种二十面体病毒，直径约170nm。类似虹彩病毒。病鱼发病的症状及流行特点也与病毒病类似。采用防病毒措施后鱼苗死亡率明显下降。因此，初步认为本次红鼓鱼鱼苗爆发性疾病的主要致病因素为该病毒。     

大黄鱼白点病及其防治方法

大黄鱼为石首鱼科黄鱼属,俗称黄瓜鱼.其肉质细嫩,味道鲜美,营养丰富,是福建省独具特色的海水网箱养殖的主要品种.罗源湾位于福建罗源县东南部,半封闭型海湾,潮汐动力强,湾内水面平静,海床格局稳定,是水产养殖的良好场所.近几年来随着人工网箱养殖规模的不断扩大和养殖密度高、网箱布局不合理以及罗源湾养殖环境变化,导致养殖病害频繁发生,限制了人工养殖大黄鱼的发展.其中寄生虫的危害重以白点病的危害最为严重,成为制约大黄鱼养殖业发展的主要因素.据调查,2005～2010年,白点病均引起了罗源湾较大的经济损失.本文就大黄鱼的刺激隐核虫引起的白点病进行介绍.     

感染鲤浮肿病毒镜鲤的组织病理变化及病毒分布规律研究

【目的】 研究感染鲤浮肿病毒（Carp edema virus,CEV）镜鲤的组织病理特征及CEV在各组织中的分布规律,以期为鲤浮肿病的诊断和防控提供参考。【方法】 利用HE染色观察发病镜鲤心脏、肝脏、皮肤、脾脏、肾脏、脑、鳃组织的病理变化情况;用免疫组织化学法检测CEV在镜鲤各组织的分布和蛋白表达情况;利用CEV P4a基因保守区域设计3条探针,于5'-端标记FAM进行原位杂交,检测CEV在镜鲤各组织的核酸分布情况;实时荧光定量PCR检测感染镜鲤各组织的病毒载量。【结果】 HE染色观察发现,患病镜鲤的鳃丝肿胀、充血,鳃丝间有脱落堆积的红细胞和炎性细胞,肝脏细胞深染萎缩,胆小管出血,脾脏组织出现明显间隙并伴有出血,肾脏组织充血明显,肾小管有明显闭合现象。免疫组织化学结果显示,在患病鱼的鳃和肝脏组织中大量表达CEV P4a蛋白,在其他组织中也有少量表达。原位杂交结果显示,CEV核酸大量存在于鳃组织中,在心脏、脾脏和肾脏中均有少量阳性信号。实时荧光定量PCR结果显示,鳃组织病毒载量极显著高于心脏、肝脏、皮肤、脾脏、肾脏、脑组织（P<0.01）。【结论】 感染CEV后,镜鲤内脏组织出现不同程度充血、出血,病毒主要分布在鳃,说明鳃是CEV增殖的最主要靶器官。     

1例猪圆环病毒病的诊断及病理组织学观察

对1例疑似患猪圆环病毒病的病猪进行临床观察和病理解剖,结果在该猪的淋巴结、肺脏中扩展出2型猪圆环病毒的特异性条带,与预期的片段大小相符,说明该猪确实存在猪圆环病毒2型(PCV-2)感染。取病死猪的心脏、肝脏、脾脏、肾脏、淋巴结等组织制作石蜡切片,H.E.染色,进行病理组织学观察,结果显示淋巴结生发中心存在嗜两性病毒包涵体。     

“如何鉴别相似鱼病”讲座(二)

第二讲 草鱼烂鳃病的种类及防治 草鱼在养殖过程中常患烂鳃病,引起草鱼烂鳃病的病因主要有三种:一是细菌——鱼害粘球菌引起细菌性烂鳃病;二是真菌——鳃霉引起的鳃霉病;三是寄生虫引起的各种鳃病,包括原生动物、粘孢子虫、指环虫和中华鳋引起的各种鳃病。 一、鳃病症状:1.由鱼害粘球菌引起的细菌性烂鳃病。鳃丝腐烂,严重时鳃软骨外露,并且常带有污泥,鳃盖内侧表面充血,中央表皮常被腐蚀成一个圆形透明小洞,俗称“开天窗”。     

一株大鳞大麻哈鱼源鲑肾杆菌的检测与鉴定

北京怀柔某养殖场的大鳞大麻哈鱼发生一种慢性,但累计死亡率很高的流行病,为研究大鳞大麻哈鱼感染病原菌的种类,本试验根据病鱼临床症状观察判断疑似感染鲑肾杆菌.试验对病鱼肾脏组织进行印片染色观察细菌形态特征,抽提病鱼的肝脏、肾脏组织DNA,扩增16S rDNA和鲑肾杆菌P57表面蛋白基因片段,测序并运用BLAST进行同源性比对.结果显示,病鱼肾脏组织印片在显微镜下可见大量形态一致的革兰氏阳性短杆菌;采用病鱼肝脏、肾脏组织扩增的16S rDNA基因构建的系统发育树显示与鲑肾杆菌聚为一支;通过PCR扩增出鲑肾杆菌P57表面蛋白基因DNA片段,测序结果与鲑肾杆菌标准株ATCC 33209完全一致,符合率为100%.结果表明病鱼感染鲑肾杆菌并引发细菌性肾病(BKD).这是中国首次在养殖鱼体内检出鲑肾杆菌.     

柱状黄杆菌弱毒株和车轮虫混合感染致金鱼烂鳃病的病原分析

【目的】确诊北京地区某养殖场金鱼发生烂鳃病的病原。【方法】采集具有临床症状的濒死金鱼,制作鳃组织的水浸片进行寄生虫和真菌观察,取肝脏、肾脏、脾脏、鳃组织开展金鱼造血器官坏死病病毒(GFHNV)检测。同时,从鳃上分离病原菌,分析病原菌的形态特征、理化特性、分类地位及药物敏感性等特性;采取鳃组织划痕浸泡和未划痕浸泡方式开展病原菌的人工感染试验。【结果】自然发病鱼鳃丝上有少量车轮虫寄生,未观察到真菌菌丝,GFHNV核酸检测呈阴性。从鳃组织分离到大量假根状菌落,该菌株为革兰染色阴性长杆菌,菌体大小(0.5～0.7)μm×(4～8)μm,氧化酶、过氧化氢酶阳性,降解明胶和硫酸软骨素,产生硫化氢,不发酵葡萄糖等糖醇类,基于16S rDNA序列构建的进化树与柱状黄杆菌聚为一枝,确认分离菌为柱状黄杆菌(Flavobacterium columnare),基因型Ⅰ型。划痕浸泡的各组金鱼均出现死亡,症状与自然发病鱼相似,划痕对照组和未划痕浸泡组均未出现死亡,经计算该菌对金鱼的半数致死量(LD₅₀)为8.8×10⁶ CFU,为弱毒株。该菌对恩诺沙星、盐酸多西环素和...     

网箱养殖大黄鱼"白肝病"防治初探

2000年4至9月，宁德地区网箱养殖大黄鱼出现大面积，大规模死亡，其主要症状为肝脏严重失血，肝组织受损，呈黄白色，并伴有烂鳃等症状，根据临床表现、检查诊断、，并结合治疗效果。本文将该病初步命名为“白肝病”现结合该病的防治，及对其产生的可能原因作初步探讨。     

1例虹鳟烂鳃病的细菌学诊断

虹鳟(Oncorhynchus mikiss)为鲑科的一类冷水性鱼,因其最适合进行人工集约化养殖,具有高产、高效、市场广阔等特点,因此虹鳟鱼养殖发展迅速,养殖面积、范围及产量逐年增长,是目前养殖最广泛的淡水鱼类之一.与此同时,由于一些常见鱼病的发生,使虹鳟养殖存在一定风险,随着养殖规模的扩大,疫病暴发频率骤增.目前,我国常见虹鳟所患疫病主要有疖疮病、弧菌病、烂鳃病、水霉病、白点病、钩头虫、鱼虱症等[1].其中,由嗜水气单胞杆菌所引发的烂鳃病流行最为广泛[2].     

猪圆环病毒2型在PMWS患猪体内分布的初步研究

利用建立的PCR方法对发生PMWS自然患猪的内脏组织中存在的PCV2病毒DNA进行检测,结果发现PCV2病毒主要存在于病猪的淋巴结、肾脏和脾脏中,在肝脏、肺脏中少量存在,心脏中最少。本研究对PCV2临床诊断和致病机理研究具有一定指导意义。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.