Prevention and treatment of porcine colibacillosis

Porcine colibacillosis is a group of intestinal infectious diseases of piglets caused by pathogenic Escherichia coli. The common diseases are yellow dysentery, white dysentery and edema disease of piglets, characterized by enteritis and enterotoxemia. Let's take a look at the prevention and treatment of porcine colibacillosis.

Pathogenesis of porcine colibacillosis

1. Endotoxin: Escherichia coli endotoxin is a lipopolysaccharide contained in the outer membrane of Escherichia coli, which is released when the bacteria disintegrate, in which lipid A has the biological function of endotoxin and is a virulent factor. the effect is obvious in septicemia.

2. Exotoxins: Escherichia coli exotoxins can be divided into two categories: heat-labile enterotoxins and heat-resistant enterotoxins. Heat-labile enterotoxin has antigenicity and high molecular weight. After 10 minutes destruction of 60 degrees, it can activate adenosine cyclase in intestinal capillary epithelial cells, increase the production of cyclic adenylate, increase the secretion of intestinal mucosal cells, diarrhea and dehydration. On the other hand, heat-resistant enterotoxin can activate the granular guanosine cyclase on the brush villi of ileal epithelial cells, increase the production of cyclic adenosine monophosphate and also cause secretory diarrhea.

3. Cytotoxin: there are three types of SLT, SLT- Ⅰ, SLT- Ⅱ and SLT- Ⅳ. At present, studies have found that SLT- Ⅱ causes clinical symptoms and pathological changes of edema disease in pigs.

Epidemic characteristics of porcine colibacillosis

1. Pig yellow dysentery: the occurrence of pig yellow dysentery is not seasonal and is closely related to environmental hygiene, such as stress factors, rainy and humid, cold and hot uncertainty, lack of breast milk, enclosure pollution, etc., can promote the occurrence of pig yellow dysentery.

2. White dysentery of son pigs: the occurrence of white dysentery of son pigs is related to the imbalance of flora and the decrease of maternal antibodies, and is closely related to various stress factors.

3. Edema disease of son pig: edema disease of son pig can be prevalent all the year round, but it occurs frequently in spring and autumn, rainy season, strong physique and good nutrition. The disease occurs mostly in pigs weighing 10 to 40 kilograms. Due to the sudden change of feed and feeding methods, rain and dampness, sudden changes in feeding methods, etc., the resistance of pigs can be decreased, which will induce the disease.

Prevention and treatment of Porcine colibacillosis

1. Strengthen the management: keep the sow delivery room clean and dry and pay attention to disinfection. 0.1% potassium permanganate can be used to scrub the nipples and breasts of sows and make the pigs eat colostrum as soon as possible. Do a good job in the feeding and management of pigs and feed ahead of time. Reduce the stimulation of various stress factors to pigs as far as possible. Do a good job in preventing cold and heat. Clean up the faeces in time, and wash the material trough and drinking sink frequently. Some studies have shown that iron supplementation can greatly reduce the incidence of yellow (white) dysentery and edema disease in pigs.

2. Vaccine immunization: Escherichia coli K88ac-LTB bivalent genetic engineering vaccine, newborn porcine diarrhea Escherichia coli K88, K99 bivalent genetic engineering vaccine, porcine Escherichia coli diarrhea K88, K99, 987p trivalent inactivated vaccine, MM-3 engineering vaccine (containing two protective antigens of K88ac and non-toxic enterotoxin LT) were used for immunization.

3. Drug treatment: because Escherichia coli is easy to produce drug resistance, especially the widespread use of antibiotics in recent years, the number of drug-resistant strains is increasing. Therefore, before treating sick pigs, it is best to isolate pathogenic Escherichia coli for drug sensitivity test in order to select the antibiotics with the best bacteriostatic effect. In order to slow the development of drug resistance, it is best to rotate the use of several different drugs. At the same time, the simultaneous treatment of mother and son is also an ideal method for the treatment of white dysentery in pigs.