What are the prevention and treatment methods for swine colibacillosis?
Swine colibacillosis is a group of intestinal infectious diseases in piglets caused by pathogenic Escherichia coli. The three common types are piglet yellow scour, piglet white scour and piglet edema disease, characterized by enteritis and enterotoxemia. Let's take a look at the prevention and treatment methods for swine colibacillosis below!
Pathogenesis of Swine Colibacillosis
1. Endotoxin: Escherichia coli endotoxin is the lipopolysaccharide contained in the outer membrane of Escherichia coli, released when the bacterial cells disintegrate. Its lipid A component has the biological function of endotoxin and is a virulence factor, with a particularly obvious role in septicemia.
2. Exotoxin: Escherichia coli exotoxins are divided into two major categories. The first category is heat-labile enterotoxin and heat-stable enterotoxin. Heat-labile enterotoxin is antigenic and has a large molecular weight; it is destroyed at 60 degrees after 10 minutes. It can activate adenylate cyclase in intestinal capillary epithelial cells, increase cyclic adenosine monophosphate production, cause hypersecretion of intestinal mucosal cells, and lead to diarrhea and dehydration. Heat-stable enterotoxin can activate particulate guanylate cyclase on the brush border of ileal epithelial cells, increase cyclic adenosine monophosphate production, and likewise cause secretory diarrhea.
3. Cytotoxin: SLT has 3 types, SLT-I, SLT-II and SLT-IV. Current research has found that SLT-II causes the clinical symptoms and pathological changes of edema disease in pigs.
Epidemiological Characteristics of Swine Colibacillosis
1. Piglet yellow scour: The occurrence of piglet yellow scour has no seasonality and is closely related to environmental hygiene. Factors such as stress, rainy and damp conditions, unstable cold and heat, insufficient breast milk, and dirty pens can all promote the occurrence of piglet yellow scour.
2. Piglet white scour: The occurrence of piglet white scour is related to dysbiosis of the bacterial flora and a reduction in maternal antibodies, and is closely related to various stress factors.
3. Piglet edema disease: Piglet edema disease can occur in all four seasons, but is more common in spring and autumn and in rainy seasons. It mostly occurs in piglets with a strong physique, good nutrition and a body weight of 10-40 kg. It is often induced by sudden changes in feed and feeding methods, rainy and damp conditions, and sudden changes in rearing methods, which can reduce the resistance of piglets.
Prevention and Treatment Methods for Swine Colibacillosis
1. Strengthen management: Keep the sow farrowing room clean and dry, and pay attention to disinfection. Use 0.1% potassium permanganate to wipe the sow's teats and udder, and make sure piglets suckle colostrum as early as possible. Improve the feeding management of piglets and provide creep feed early. Minimize the stimulation of various stress factors on pigs. Do a good job of cold and heat protection. Clean up manure in a timely manner, and scrub the feed trough and water trough frequently. Studies have shown that iron supplementation can greatly reduce the incidence of piglet yellow (white) scour and edema disease.
2. Vaccine immunization: Vaccination can be carried out with vaccines such as the Escherichia coli K88ac-LTB bivalent genetically engineered bacterial vaccine, the neonatal pig diarrhea Escherichia coli K88, K99 bivalent genetically engineered bacterial vaccine, the piglet Escherichia coli diarrhea K88, K99, 987P trivalent inactivated vaccine, and the MM-3 genetically engineered bacterial vaccine (containing two protective antigen components, K88ac and non-toxic enterotoxin LT).
3. Drug treatment: Because Escherichia coli readily develops drug resistance, especially with the widespread use of antibacterial drugs in recent years, drug-resistant strains have continued to increase. Therefore, before treating sick pigs, it is best to isolate the pathogenic Escherichia coli and conduct a drug sensitivity test to select the antibiotic with the best antibacterial effect. In order to slow the development of drug resistance, it is best to rotate several different drugs. At the same time, treating both the sow and the piglets is also a relatively ideal method for treating piglet white scour.