How to prevent swine dysentery

Porcine dysentery is an acute infectious disease caused by Treponema pullorum, which is characterized by varying degrees of mucinous hemorrhagic dysentery (commonly known as "blood dysentery"), weight loss and catarrhal hemorrhagic and necrotizing inflammation of the cecum.

The disease can occur all the year round, and can occur in pigs of all ages, mostly at the age of 2-3 months. The morbidity of piglets after infection can reach 75%, and the mortality rate is 5% 25%. Diseased pigs and infected pigs are the main sources of infection, and fecal pollution is the main route of infection. the bacteria-carrying rate of recovered pigs is very high, and the high bacteria time is as long as several months, which often causes the disease to continue in pigs and makes the work of disinfection and epidemic prevention more difficult.

In the first 1-2 weeks when the natural infection broke out, the disease was mostly the most acute and acute, mainly hemorrhagic dysentery in clinic, then gradually changed to subacute and chronic, and mainly mucinous diarrhea in clinic.

The most acute cases often die suddenly, a sign that pigs are beginning to break out of the disease. At the beginning of the disease, the spirit was slightly poor, the appetite decreased, the feces hardened, and the surface was attached with conditional milky mucus, followed by acute symptoms, rapid dysentery, yellow, soft or watery stool. 1-2 days later, the stool mixed with more blood and mucus, or there were blood clots, the body temperature increased to 40 ℃-42.5 ℃, and decreased to normal after a few days. The diseased pig has depressed spirit, pale skin, and increased fragments of blood, mucus and necrotic epithelial tissue in the feces. Sick pigs gradually lose weight, have a sunken abdomen, and may eventually become weak and die.

In subacute and chronic cases, the condition is mild, diarrhea, less blood in stool, and more mucus and necrotic epithelial tissue fragments, or no dysentery, and the stool is dark red with more blood. The disease has a long period of disease, progressive weight loss, pale skin, stagnant growth and low mortality.

The pathological changes were only limited to the large intestine and were often limited to the colon, congestion and edema of the intestinal wall and mesentery, and enlargement of mesenteric lymph nodes with obvious white granules. Large intestinal mucosa congestion, bleeding and swelling, often covered by jelly mucus and fibrin exudate with blood clots, severe surface mucosal necrosis, the formation of false membrane, showing a wheat bran or bean curd-like appearance.

Clinically, according to the above-mentioned symptoms and changes of autopsy, it is easy to make a preliminary diagnosis, and laboratory examination is needed for diagnosis.

Clinically, porcine dysentery must be distinguished from other dysentery diseases: porcine viral diarrhea is characterized by watery diarrhea and dehydration with fishy smell, and salmonellosis is characterized by bleeding and necrosis of small intestine and large intestine. Intestinal colibacillosis is characterized by watery dysentery without blood or mucus.

Prevention and treatment:

(1) dysentery Jing, intramuscular injection or oral administration, once a day for 3-5 days as a course of treatment. The two drugs are often used interchangeably to prevent drug resistance. Feeding the same dose of mixture for 3 days a month can prevent the occurrence of the disease.

(2) acridine yellow hydrochloride (yellow pigment), oral 1.5-2.5 mg per kilogram of body weight, once a day for 2 days. Or slow intravenous injection of 3-5 mg per kilogram of body weight (maximum 0.5 g). In severe cases, it will be injected again after 3 days.

(3) strengthen cleaning and disinfection and deal with feces.