Influence of Diet on Experimental Swine Dysentery. 3. Pathological Changes

Three experiments have been carried out to elucidate the possible influence of the vitamin E and selenium content of the feed on experimental swine dysentery. In most of the pigs given a vitamin E and selenium deficient diet, large and diffuse pseudomembranes appeared in the spiral colon, which also usually displayed a distended appearance and prominent oedematous infiltrations in the mesentery. The histological examination revealed large fibrinous pseudomembranes attached to defects on the mucosal surface. There were also pseudo-membranes containing necrotic mucosal tissue. Fibrinoid thrombi within minute vessels were readily observed in the latter lesions. The vitamin E supplemented pigs had colonic lesions very much like the deficient animals, while half of the selenium supplemented animals developed none or moderate inflammatory changes, the other half displayed, however, prominent pseudomeinbranes in the colon. Ten out of 26 pigs supplemented with both vitamin E and selenium were not affected by swine dysentery. In the remaining pigs catarrhal inflammatory lesions dominated in the colonic mucosa. In some of these animals pseudomembranes occurred, but they were usually small and of limited distribution. The vascular thromboses and tissue necrosis demonstrated within the colonic lesions are found to be compatible with a Shwartzman reaction. Erythrocytic “thrombi” and other phenomena associated with stasis are further believed to be of pathogenetic importance in this respect. It is emphasized that this report also illustrates the enhancing effect of a combined supplement of vitamin E and selenium on resistance to swine dysentery.     

鸡氟中毒临床及病理学观察

由于在饲料中使用劣质的骨粉和未经脱氟处理的磷酸氢钙作为钙磷补充剂，我国许多地区出现了大量氟中毒病例。河北省玉田县某养鸡户因饲料中添加从当地市场购买的劣质磷酸氢钙引起鸡大批死亡。为确诊其中毒原因，我们特进行了鸡中毒试验，并对饲料中添加的磷酸氢钙中氟含量进行了检测。     

猪痢疾检疫方法概述

猪痢疾是由致病性密螺旋体引起的一种猪肠道传染病,其特征为黏液性或黏液出血性下痢,大肠黏膜发生卡他性出血性炎症,有的发展为纤维素性坏死性炎症。目前,控制本病主要采取综合防制措施,所以,有必要对该病进行检疫,及早阻断病原传播。     

猪弓形虫病诊断及临床病理学研究

对一起猪病进行了流行病学调查和临床病理学研究，同时结合血清学和PCR检测，结果表明，该起猪病是由弓形虫感染引起。临床症状：高热稽留，呼吸困难，体表发紫，先便秘后腹泻，共济失调，最后衰竭而死亡；病理变化特征：肺水肿、间质性肺炎，坏死性脾炎，局灶性坏死性肝炎和淋巴结炎，非化脓性脑炎以及间质性肾炎等。     

人工感染堆型艾美耳球虫的雏鸡小肠病理学观察

本试验利用常规病理学方法,对人工感染5×104个堆型艾美耳球虫卵囊的雏鸡,在感染该球虫后7 d,即在堆型艾美耳球虫的一个生理周期内,对雏鸡的病理变化进行观察。眼观所见主要病理变化为小肠前段充血,肠壁变薄,苍白色,内容物含浆液量增多。病理组织学变化主要为小肠前段黏膜层有脱落,绒毛上皮细胞有变性、坏死、脱落,不同时期细胞内含有多量不同发育阶段的虫体。     

急性非洲猪瘟的实验病理学研究

旨在通过对非洲猪瘟临床病理学和组织病理学的研究,探讨病理学变化与疾病发生发展的内在关系及其病理机制。选用体重20 kg左右的长白猪13头,肌内注射非洲猪瘟病毒毒株Pig/HLJ/18,剂量10²HAD₅₀·mL^-1。试验期间的死亡猪,全部进行系统剖检和取材,制备石蜡切片,苏木素伊红染色。建立病理学评价标准,病变（无序分类变量）用频率和百分比表示,病变程度（有序分类变量）按各组织器官的不同病变进行分级和评分。结果表明,发病猪符合非洲猪瘟急性、热性、高传染性等临床特征,发病率100%,病死率100%。病死猪表现败血症典型特征,尸体易腐败,血凝不良或溶血,尸僵不全。主要病理损伤为出血性坏死性淋巴结炎、急性炎性脾肿（败血脾）、脑水肿、肺水肿和肺实变等。脾和淋巴结是非洲猪瘟病毒攻击的靶器官,病变最为显著,出现时间最早,持续时间最长,发生频率最高。病理变化以血液循环障碍尤为突出,包括水肿、充血、淤血、出血、梗死和弥散性血管内凝血等多种病理表现,出血性病变为其最主要的特征。非洲猪瘟病毒引发的以淋巴细胞渗出为主的炎症反应贯穿始终,在病程的中后期表现更为明显。结果提示,急性非洲猪瘟的主要病理过程为典型的免疫/炎症级联反应和严重的全身血液循环障碍,共同导致急性非洲猪瘟的高发病率和高死亡率。     

Experimental Pathological Study of Acute African Swine Fever

To study the clinicopathology and histopathology of African swine fever (ASF), and to explore the internal relationship between pathological changes and disease occurrence and development and its pathological mechanism, 13 Landrace pigs with bodyweight about 20 kg were intramuscular injected with African swine fever virus (ASFV), strain Pig/HLJ/18 at a dose of 10²HAD₅₀·mL^-1. During the experiment, all the dead pigs were systematically dissected and sampled, paraffin sections were produced, and haematoxylin-eosin staining was performed. Clinicopathological evaluation standards for acute ASF were established, then pathological lesions (classification variables) were expressed by counting frequency and percentage, and the lesion degree (continuous variables) was graded and scored according to different pathological changes of various tissues and organs. The results showed that all infected pigs were in line with the clinical characteristics of ASF, including acute, febrile and highly infectious, with a 100% incidence rate and 100% mortality. The dead pigs showed typical characteristics of septicemia, cadavers prone to corruption, blood clotting adverse or hemolysis, rigor mortis incomplete. The main pathological lesions were hemorrhagic necrotizing lymphadenitis, acute inflammatory splenomegaly (septic spleen), cerebral edema, pulmonary edema and lung consolidation et al. The spleen and lymphonodus are the target organs attacked by ASFV, with the most significant lesions, the earliest occurrence time, the longest duration and the highest frequency. The most prominent pathological changes are blood circulation disorders, including multiple pathological manifestations such as edema, hyperemia, congestion, hemorrhage, infarction, disseminated intravascular coagulation (DIC), and the most important characteristics are hemorrhagic lesions. The inflammatory reaction of lymphocytic exudation caused by ASFV runs through the whole process, especially in the middle and later stages of the course. The results suggest that the main pathological process of acute African swine fever is a typical immune/inflammatory cascade reaction and severe systemic blood circulation disorder, which resulted in the high incidence rate and high mortality rate of acute ASF.     

Clinical Evaluation of Tylosin as a Treatment of Vibrionic Dysentery in Swine

A 5 year history of swine dysentery and treatment has been described.     

Therapeutic Effect of Lincomycin and Spectinomycin Water Medication on Swine Dysentery

The therapeutic effects of various water medications on swine dysentery were determined in 223 pigs under controlled conditions. Carrier pigs were mixed with test animals until the disease was established. Lincomycin (22 mg/liter), spectinomycin (44 mg/liter) alone and lincomycin and spectinomycin in combination (66 mg/liter) and sodium arsanilate (161 mg/liter) in drinking water for seven days were the drugs evaluated. Negative and positive controls were also included. The experiment was terminated 41 to 43 days after initial medication. Mortality, mean value for stool consistency, incidence of dysenteric days and gross lesions of swine dysentery were the parameters measured for each treatment group.

The lincomycin-spectinomycin water medication was effective for the treatment of swine dysentery. Pigs treated with lincomycin-spectinomycin had a higher survival rate, a lower incidence of dysenteric days and fewer gross lesions of swine dysentery than pigs treated with sodium arsanilate, lincomycin or spectinomycin alone or the infected controls (P < 0.05).

     

Transmissible Gastroenteritis in Feeder Swine: Clinical, Immunofluorescence and Histopathological Observations

Eight feeder swine (four to six months of age) were inoculated orally with 200,000 to 500,000 pig infectious doses (PID) of the Purdue strain of transmissible gastroenteritis (TGE) virus. Biopsies obtained from their small intestines were examined histopathologically and by fluorescent antibody tissue section technique at intervals that included 24, 48, 72 and 96 hours postexposure, and similar examinations were carried out at necropsy 168 hours postexposure. Evidence of virus infection was demonstrated in all segments of the small intestine except the upper duodenum and the viral antigen was found only in the cytoplasm of the absorptive cells covering the villi. Although six of the eight pigs failed to show clinical signs of TGE, typical microscopic lesions of villous atrophy with replacement of columnar absorptive cells by cuboidal cells were observed in seven pigs, and TGE virus antigen was demonstrated in the intestinal cells of four of eight pigs during the first week postexposure. The infection was usually mild to moderate and focal in the pigs without clinical signs of the disease and more severe and extensive in the pigs with clinical signs of the disease variable in severity. It was concluded that TGE virus probably replicated in all feeder swine exposed, and that the presence or absence of clinical signs of TGE in these pigs was related to the severity and extent of the villous atrophy and columnar cell replacement induced in their small intestines.     

Observations on a Swine Herd Health Program

Observations on a swine herd health program are reported. A primary purpose was to show that such programs could provide economic benefits to swine breeders and sources for breeding stock of minimum disease status. The possible influence of diseases of swine, including atrophic rhinitis and virus pneumonia, on both aspects are discussed. The inadequacy of knowledge of diseases of swine, both specifically and generally, is pointed out. Veterinary supervision of a swine herd will result in economic benefits to an average capable owner. There is both merit and need for such programs, but as to what health standards would be reasonable, practical, and meaningful, is still not clearly defined.     

Some Observations on the Diagnosis and Epidemiology of Leptospirosis in Swine

The results of combined epidemiological, clinical, serological, bacteriological and histopathological studies following an outbreak of disease caused by L. pomona on a farm stocked with cattle, sheep, pigs, goats and horses maintained for experimental purposes, are reported.

The incidence of infection was high in horses, cattle and pigs. A few low titres were seen in sheep. The goats were not infected. Apart from a single bovine abortion all the clinical symptoms observed occurred in pregnant sows. Seven of these aborted or gave birth to stillborn pigs within a six week period.

Fifteen species of wildlife were trapped or shot on the farm during the year following the outbreak. L. pomona was isolated from four skunks and a porcupine. Epidemiological studies indicated that wildlife reservoir hosts were the primary source of infection for the domestic livestock.

Leptospiruria and the serological response were studied in a group of eight infected sows. Microscopic agglutination titres of 10² or less could not be associated with leptospiruria and the duration of leptospiruria was found to range from a few weeks to over two years in individual sows. Direct dark-field examination of urine proved superior to guinea-pig inoculation as a method of detecting leptospiruria and it is suggested that the former technique could be adopted with advantage as a routine aid to diagnosis.

     

猪旋毛虫病膈肌的病理形态学观察

对80份猪旋毛虫病膈肌进行了病理组织学和组织化学观察,并对其中5份作了透射电镜观察。结果:膈肌旋毛虫病灶的病变分为非包囊型、包囊型、包囊性肉芽肿型、肉芽肿型和淋巴细胞结节型等5种类型;旋毛虫包囊壁内、外两层的成分是胶原,内层来源于感染肌纤维,外层为增厚的感染肌纤维的基底膜;感染和非感染肌纤维,均具有变性和再生变化,但前者的再生最后形成包囊,而后者则一般以结缔组织取代之;感染和非感染肌纤维均有一定的碱性磷酸酶活性,尤以肌膜最明显,而非特异性酯酶仅位于旋毛虫病灶内;旋毛虫病灶内,T、B淋巴细胞同时存在,且尚见嗜酸性白细胞。     

疑似猪瘟病例的病理学诊断

对送检的42例疑似猪瘟或伪狂犬病病例样品进行了病理学诊断。样品主要包括扁桃体、淋巴结、脾脏、肺脏、肾脏、肠、脑等,通过甲醛固定,石蜡切片,H.E.染色后进行显微镜下观察,结果显示,主要的病理变化包括扁桃体炎、脾炎、淋巴结炎、肠炎、肺炎、肾小球分叶增多、脑膜脑炎,未见伪狂犬病嗜酸性包涵体。结合相关病理学知识,初步判定疑似猪瘟。     

Cyclic Related and Pathological Changes in the Lectin-binding Sites on the Swine Oviduct

This study was carried out to compare the lectin-binding pattern in the normal and pathological oviduct of sows during the ovarian cycle. Lectin-binding patterns showed differences between segments, phases of ovarian cycle and presence of morphologic lesions. In the infundibulum, it was observed that the cysts, in the follicular phase, reduced Ricinus communis-I (RCA-I) and Ulex europaeus-I (UEA-I) binding. Furthermore, in the pathological oviducts of the luteal-phase group, there is a reduction of Concanavalia ensiformis (Con-A) reactivity in this segment of the tube having wall cysts, adenomyosis and diverticulus. The Arachis hypogaea (PNA) binding in the infundibulum, during the luteal phase, decreased in the tube having adenomyosis. In animals with wall cysts, the Con-A, Triticum vulgaris (WGA) and RCA-I reactivity was minor in the glycocalyx of the isthmus epithelium during follicular phase. Con-A and Dolichos biflorus (DBA) binding pattern was minor in the luteal-phase isthmus of the tube having wall cysts, adenomyosis and diverticulus. In the ampulla, the wall cysts impaired the Con-A reaction only in the basal region of the epithelium, in the follicular phase. Binding with Con-A was decreased in the ampulla of animals in the luteal phase in the tube lesions with cysts and diverticulus. In addition, the diverticulus observed in the ampulla, during the luteal phase, reduced the PNA tubaric binding. The results of this study showed that the morphologic alterations modify the sugar pattern in the oviduct of sows. These modifications in glycoconjugates may be one of the reasons for the failure of fertility in sows.     

非典型猪瘟的病理学检查及诊断

猪瘟是由猪瘟病毒所引起的传染性强、病死率高的烈性传染病，在世界上许多养猪国家均有不同程度的流行［１］，是国际兽疫局规定必需检疫的Ａ类传染病，为此各国都致力于消灭猪瘟的工作。我国５０年代后由于兽医科技人员的一致努力，通过广泛的免疫接种，基本上控制了本病的发生与流行。但８０年代以来我国的猪瘟疫情又有重新抬头趋势，随着普遍的猪瘟疫苗的免疫接种，猪体内存在不同程度的免疫抗体。近两年猪瘟的发病形式和特征都有所变化，急性病程及较大规模的暴发流行已较少发现，而代之以病程较长、症状病变轻微不显著的所谓“非典型猪…     

上海市生猪屠宰检疫和门诊出诊中猪肺脏的病理性观察

近年来,由于生猪饲养方式的改变,种猪、商品猪及猪产品流通加剧等方面的原因,猪的疾病日趋严重和复杂化,一些新发疫病及其原有疫病的混合感染也日渐增多。现代化集约化养猪体系由于生产规模和饲养密度加大,而相对应的设施设备改进不够,猪舍小气候环境显著变坏,引起猪应激反应明显增加,造成猪机体抵抗力下降,导致呼吸系统传染病的发生越益频繁。猪呼吸道疾病综合征(Porcine respirato-ry disease complex,PRDC)是一种多因素引起的呼吸道疾病的总称,它是由病毒、细菌、环境应激和猪体免疫力低下等因素相互作用而造成的。PRDC涉及几种引起…