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
Enteric Diseases of Young Pigs 仔猪肠道疾病
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
仔猪肠道疾病
Definition of Diarrhea 下痢的定义
仔猪肠道疾病
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
Selecting Segments of Intestine 肠段的选择
Fresh samples样本要新鲜
7 – 10 cm segments of ileum, jejunum7～10厘米回 肠和空肠的肠段
Segment of spiral colon结肠螺旋襻的肠段
仔猪肠道疾病
Causes of pig diarrheas 仔猪肠炎原因
Colon serves to conserve water and electrolytes 结肠只起吸收水和电解质的作用
仔猪肠道疾病
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
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
仔猪肠道疾病
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
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
仔猪肠道疾病
Arriving at a Diagnosis诊断
History病史
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
仔猪肠道疾病
仔猪肠道疾病
E. coli 大肠杆菌
Rotavirus 轮状病毒
C. perfringens
产气荚膜梭状芽孢杆菌
TGE 传染性胃肠炎 Coccidiosis 球虫病
Source-Iowa State Diagnostic Lab 2000-2002
Nursing 断奶前
11% 14% 19%
8% 20%
仔猪肠道疾病
Undigested ingesta ferments未消化的食糜发酵
仔猪肠道疾病
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
●实验室—用琼脂平板培养大肠杆菌 culture E. coli on agar plate
Weaning 断奶后
49% 12% 0%
7% 15%
仔猪肠道疾病
Colibacillosis - E. coli
大肠杆菌病
● 分泌过度性下痢 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
间死亡的猪采集病料
仔猪肠道疾病
仔猪肠道疾病
仔猪肠道疾病
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
Increases severity in succeeding litters ● 头胎仔猪可能更严重
Gilt litters may be more severe
仔猪肠道疾病
Diagnosis - E. coli
大肠杆菌病诊断
● 进行性水样下痢 progressive watery diarrhea
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