仔猪肠道疾病.ppt

Enteric Diseases of Young Pigs仔猪肠道疾病,Diarrhea remains one of the leading causes of neonatal mortality in swine下痢一直是新生仔猪死亡的主要原因,Definition of Diarrhea下痢的定义,Excess water in feces relative to dry matter.粪中含水量过大Normally,much of the fluid is absorbed in the small intestine before it exits the ileum 通常，大部分水都在进入回肠之间就在小肠中被吸收了Colon serves to conserve water and electrolytes结肠只起吸收水和电解质的作用,Mechanisms of Diarrhea下痢的机理,Secretory Diarrhea分泌性下痢Result of the effect of enterotoxins secreted by bacteria and some viruses细菌和其它病毒分泌的肠毒素造成的结果Alteration in secretion of electrolytes,water,and bicarbonate:gradient pulls water into lumen电解质、水和碳酸氢钠的分泌发生改变：使水进入肠腔Absorption continues:Chyle in lymphatics,Mechanisms of Diarrhea下痢的机理,Malabsorptive Diarrhea吸收不良性下痢Reduction in surface area of intestine肠粘膜表面积减少Loss of absorptive capacity吸收能力减弱Villous atrophy绒毛萎缩Chyle absent in lymphatics淋巴乳糜缺乏Undigested ingesta ferments未消化的食糜发酵,Mechanisms of Diarrhea下痢的机理,Effusive Diarrhea渗漏性下痢Result of severe damage to mucosa粘膜严重受损的结果Necrotoxins produced by bacteria细菌产生的坏死毒素Leakage of serum proteins and water due to vascular damage血管受损导致血清蛋白质和水漏出Loss of absorptive capacity吸收能力减弱,Arriving at a Diagnosis诊断,History病史Age of onset发病年龄Vaccination history免疫接种历史Sudden death vs.protracted diarrhea猝死和长期下痢,Arriving at a Diagnosis诊断,Selection of specimens病料采集Diarrhea of 24 hrs or less下痢开始后24小时以内Untreated未经治疗Avoid pigs which“died during the night”不要从夜间死亡的猪采集病料,Selecting Segments of Intestine肠段的选择,Histopathology组织病理学Sections representative of all areas of intestines要选择能代表肠道所有区域的部分Better to have many small pieces than one large piece最好要采集多个较短肠段，而不要只采集一个很长的肠段Segments 1 cm long,opened lengthwise根据纵向尺寸的不同，采集1厘米左右的肠段,Fresh samples样本要新鲜7 10 cm segments of ileum,jejunum710厘米回肠和空肠的肠段Segment of spiral colon结肠螺旋襻的肠段,Selecting Segments of Intestine肠段的选择,Causes of pig diarrheas仔猪肠炎原因,NursingWeaning断奶前断奶后E.coli 大肠杆菌 11%49%Rotavirus 轮状病毒 14%12%C.perfringens 19%0%产气荚膜梭状芽孢杆菌TGE 传染性胃肠炎 8%7%Coccidiosis球虫病 20%15%Source-Iowa State Diagnostic Lab 2000-2002,Colibacillosis-E.coli大肠杆菌病,分泌过度性下痢 Hypersecretion diarrhea12小时至34天龄或更大的猪下痢 Diarrhea from 12 hours to 3-4 days 可能极度水样化 May be extremely watery 随后发病的各窝猪更严重 Increases severity in succeeding litters 头胎仔猪可能更严重 Gilt litters may be more severe,Diagnosis-E.coli大肠杆菌病诊断,进行性水样下痢progressive watery diarrhea实验室用琼脂平板培养大肠杆菌 culture E.coli on agar plate用分离的大肠杆菌作敏感性测定 culture and sensitivity testing,Diarrhea Treatments 下痢的治疗,Gentamycin庆大霉素Spectinomycin 壮观霉素Kanamycin 卡哪霉素Neomycin 新霉素Sulfa,trimethoprim 磺胺，三甲氧苄氨嘧啶,Colibacillosis vaccines大肠杆菌疫苗,菌苗含有最常见的致病性菌株 在母猪产前的5周和 2周注射 此后的母猪只需产前2周注射一次疫苗应该含有K88,K99,987P,F41。Bacterin-most common pathogenic strainsInject sows 5 weeks and 2 weeks prior to farrowingSubsequent farrowings-2 weeks only,Clostridium perfringens type CC型产气荚膜梭状芽孢杆菌,12 hrs 7 days12小时7天Death in as little as 4-8 hours48小时内死亡Bloody or yellow to gray diarrhea带血或黄色至灰色下痢Necrotoxins坏死毒素,Clostridium perfringens type A A型产气荚膜梭状芽孢杆菌,Watery to pasty,white to yellow diarrhea水样至粘性下痢，白色至黄色Toxins毒素-2 often seen in isolates from pigs with diarrhea下痢仔猪分离到的菌株常见-2毒素Lesions similar to those with type C病变与C型所致的病变相似Necrosis of tips of villi绒毛顶端坏死Lack hemorrhage无出血,Prevention and Treatments预防和治疗,Vaccinate sows 5 and 2 weeks prior to farrowing May require development of an autogenous vaccine分娩前5周和2周对母猪免疫，可能需要生产自家菌苗Feeding antibiotics such as bacitracin to sows prior to farrowing分娩前对母猪饲喂杆菌肽等抗生素Treat piglets at birth with penicillin or antiserum在仔猪出生时用青霉素或抗血清对其进行治疗,TGE传染胃肠炎,Highly contagious viral disease 高度传染性病毒病Can result in 100%mortality 能引起100%死亡Survival depends on the age of the pig存活取决于猪的年龄Endemic forms can develop 可能成为地方流行性,TGE 传染胃肠炎,Cause is a coronavirus 病原为冠状病毒Attacks cells lining the small intestine 攻击小肠内壁细胞Survives for long periods of time in the environment 在环境中可长期存活Very stable when frozen 冰冻后非常稳定生存,TGE 传染胃肠炎,TGE 传染胃肠炎,Inactivation of the virus 病毒的灭活sunlight 阳光drying 干燥warm temperatures 高温most disinfectants 多数消毒药,TGE Clinical Signs 传染胃肠炎临床症状,Severe diarrhea 严重的下痢Vomiting 呕吐Dehydration 脱水High mortality in young pigs under 2 weeks of age 两周龄以下的猪死亡率高Lower mortality in pigs over 3 weeks of age 三周龄以上的猪死亡率低,TGE Spreads Rapidly 传染胃肠炎传播快,Very short incubation period 潜伏期很短Within 2-3 days majority of pigs on farm can be infected 2-3天内猪场内多数猪即被感染,Sources of Infection 传染胃肠炎传染源,Primarily infected shedding pigs 主要为受感染的排毒猪People second most important 人是第二重要的传播因素Starlings and other animals 椋鸟科鸟和其它动物,Diagnosis of TGE 传染胃肠炎诊断,Clinical signs 临床症状Necropsy 病理剖检Diagnostic Laboratory 实验室诊断histological confirmation 病史确认positive FA test 荧光抗体阳性检测,Treatment of TGE 传染胃肠炎治疗,Keep warm 保暖Antibiotics to control secondary bacteria 应用抗生素防止继发感染Wean pigs early 早期断奶Young pigs rarely survive despite treatment efforts 尽管进行治疗，年龄小的猪仍然很少存活。,TGE Immunization 传染胃肠炎免疫,Deliberate entire herd exposure to virus 故意让整个猪群接触病毒Timing is important 上述处理的时间很重要Is infection in farrowing facility?产房内有无感染?Goal is to shorten the overall effect 目标是减轻整体影响,TGE Immunization 传染胃肠炎免疫,If not in farrowing facility 如果产房内无感染Isolate these facilities from the rest of the farm 将产房与场内其他猪舍隔离开Expose other sows on the farm 自然免疫场内的其它母猪,TGE Vaccines 传染胃肠炎疫苗,Injectable 注射型Oral 口服型Variable protection to piglets through the colostrum 通过初乳对仔猪提供的免疫力强弱不一,Autogenous TGE Vaccine 传染胃肠炎自家疫苗,Harvest intestines from acutely infected piglets when clinical signs appear 当出现临床症状时，收集急性感染仔猪的小肠Homogenize in a blender 放在组织粉碎机内制成匀浆Material can be frozen for later use 冰冻保存备用,Autogenous TGE Vaccine Use传染胃肠炎自家疫苗的应用,One piglets intestines per 20 sows in 2 1/2 liters of water,125cc(1/2 cup)per sow mixed in feed 每20头母猪饲喂一头仔猪的肠道组织，肠道组织匀浆溶于2.5升水中；每头母猪125毫升(半杯)混入饲料中。Feed to sows at least 3 weeks prior to farrowing 至少在分娩前三周投喂母猪Planned exposure to specific groups may not be contained 可以不包括对特定年龄组猪的计划性感染,Autogenous TGE Vaccine Use 传染胃肠炎自家疫苗的应用,Exposure to entire herd may eliminate the virus from the farm 饲喂整个猪群可能会根除猪场内的病毒Eliminates carrier pigs 清除带毒猪Virus dies out 病毒死亡Best done during hot weather 最好进行于天气炎热时,Enzootic(chronic)TGE 地方性(慢性)传染胃肠炎,Diarrhea in 7-14 day old piglets 714日龄的猪表现腹泻Post weaning in the nursery 断奶后的保育仔猪Not all pigs or litters affected 不是所有的猪或窝都被被感染Vomiting is rare 极少发生呕吐Sows not sick 母猪不发病,Dealing With Enzootic TGE 对付地方性(慢性)传染性胃肠炎,Entire herd exposure 令整个猪群接触病毒All-in/All-out production 全进全出的生产系统Good sanitation and disinfectant 良好的卫生和消毒措施Footbaths to reduce spread of virus 实施脚浴以减少病毒传播,Rotavirus 轮状病毒,黄色至白色下痢 Yellow to white scours 危害10日龄至3周龄的仔猪Affects 10 day to 3 week old pig除非受感染的幼猪，否则死亡率低。Mortality low unless younger pigs affected发病率-100%Morbidity-100%,Coccidiosis 球虫病,猪等孢球虫(Isospora suis)在热天时发病增多 Incidence increase during hot weather发病率：水泥及木板地面 100%发病Morbidity-100%on concrete or wood floor死亡率020%Mortality 第一胎的仔猪较易发病 gilt litters,Coccidiosis:Diagnosis 球虫病诊断,Histopathology 组织学 病原学 Intestinal smear 小肠涂片Fecal flotation 粪便漂浮法检查,Coccidiosis-Prevention 球虫病预防,金属丝网状地面 wire floors极好的卫生 extremely good sanitation漂白剂或氨水消毒 bleach or ammonia(例如：次氯酸钠)sodium hypochlorite 冲洗母猪 wash sow 远离病圈 stay out of pens,Control&Treatment of Pig Diarrheas仔猪下痢治疗与预防,Diagnosis诊断Antimicrobials抗菌药Electrolytes 电解质Extreme sanitation 高度卫生All-in,all-out 全进全出Immunizations 免疫接种,