How to prevent and control common intestinal diseases in pig farms

There are many kinds of pig intestinal diseases and the etiology is complex, which has caused great harm to pig production. This paper gives a brief overview of the types, causes, prevention and treatment of diseases for reference to pig farms.

Species:

There are 6 different serotypes of porcine enterovirus infected with porcine enterovirus. Infection is usually acquired when the maternal antibody disappears shortly after weaning and when several litters of piglets are mixed together. Different clinical symptoms are related to different serotypes, such as poliomyelitis, reproductive disorder, diarrhea, pneumonia, pericarditis, myocarditis and so on. Piglets with severe infection can show focal myocardial necrosis.

Rotavirus infection occurs mostly in pigs under 8 weeks of age, with a high mortality rate of 50%. The sick pigs are depressed and unwilling to move around. At the initial stage of the disease, they often vomit after eating, and the drainage sample or paste yellow-white or grayish brown faeces often die within 3 ~ 7 days because of dehydration. Autopsy showed that the stomach was full of curd, mucous membrane fell off, and some small intestinal mucosa of diseased pigs were congested or bleeding. At present, there is no specific drug or preventive vaccine. In endemic areas, newborn pigs eat colostrum as early as possible to be protected by maternal antibodies.

Intestinal adenoma complex sign, also known as porcine proliferative bowel disease, is more common in 3-8-day-old pigs. According to the characteristics of the lesions, they can be divided into four types: intestinal adenomatosis, necrotizing ileitis, local ileitis and proliferative hemorrhagic enteritis. The clinical manifestations were lethargy, loss of appetite, severe diarrhea, weight loss, rough coat and anemia in diseased pigs. If the course of the disease is prolonged, black tar-like feces will be excreted, which will gradually fade; some pigs do not show abnormal feces, but the visual mucosa is pale.

Yellinella disease occurs frequently in summer and winter and is sporadic. The incubation period of diseased pigs is 2 ~ 3 days, the initial body temperature is 40 ℃ ~ 41 ℃, loss of appetite or loss of appetite, watery diarrhea, and feces often mixed with mucus and exfoliated intestinal mucosa. In the later stage, the body temperature dropped, and the skin was cyanotic, emaciated and dehydrated. Autopsy showed that the isolated lymphoid follicles of the colon and rectum were enlarged and protruded to the serous layer or mucosal layer. There are ulcers in the small colon and rectum.

The pathogen of porcine epidemic diarrhea is coronavirus, which mainly occurs in the cold season of late winter and early spring. At the beginning of the disease, the body temperature is normal or slightly elevated, mental depression, loss of appetite, drainage, grayish yellow or gray feces, sour smell, with undigested food. The symptoms of older pigs were milder. The younger pigs were prone to vomiting, porridge or watery stool, the small intestine was full of yellow contents, the intestinal wall became thinner, and the mesentery was dendritic hyperemia. The younger the pig was, the higher the mortality was.

Porcine transmissible gastroenteritis is susceptible to gastroenteritis in all ages, and it is common in pigs at the age of 2 weeks in late winter or early spring, which spreads quickly and has a high mortality. Pigs often vomited after lactation, followed by severe diarrhea and drained yellow or grayish-white feces. After weaning, the symptoms of pigs were mild, only dieting and diarrhea, and some pigs vomited after eating, but the mortality rate was low. The symptoms of fat pigs and sows were mild, showing loss of appetite, and some of them had symptoms of vomiting and watery diarrhea. Generally, diarrhea stopped after 5 ~ 8 days, and sick pigs returned to health. Autopsy showed that there were obvious catarrhal inflammation and mesenteric vascular congestion in the bottom of stomach and intestinal mucosa, and some sick pigs were complicated with pneumonia.

Porcine colibacillosis mainly includes yellow dysentery, white dysentery and edema disease. Yellow dysentery can occur in pigs within 7 days of birth, and it is common at the age of 1-3 days. Some pigs die suddenly within 12 hours or 3 days after birth. The main symptoms of the diseased pigs are yellow or yellow-white watery feces, containing curd blocks, reduced or not fed, dehydration, enophthalmos, rapid emaciation; if not treated in time, die within one or two days. White dysentery mostly occurs in pigs within 10 to 30 days of age. The feces of diseased pigs are milky white, yellowish green or grayish white, fishy, often mixed with mucus and mushy, which contain air bubbles. If left untreated, dysentery worsened, accelerated breathing, unstable walking, 5-6 days death; autopsy showed that the contents of the colon showed paste or ointment, milky white or gray, sticky and greasy There were catarrhal inflammatory changes in the small intestinal mucosa, thinning of the intestinal wall and slight swelling of mesenteric lymph nodes. Swine edema disease is more common in weaned pigs with vigorous growth and development, with eyelid edema, ataxia and neurological symptoms in the later stage.

Porcine spirochete disease, also known as porcine dysentery, porcine blood dysentery, is an infectious disease caused by Borrelia. Most of the pigs were from 7 weeks to 12 weeks old. It is characterized by mucous bleeding, dysentery and necrotizing inflammation of the large intestine. General disinfection drugs can kill this pathogen. The initial body temperature of diseased pigs can reach 40 ℃ ~ 41 ℃, and yellow or gray soft stools are excreted. In the later stage, the feces are watery, often mixed with blood, mucus and mucous membrane, making the feces greasy or jelly-like. Sick pig arch back hanging abdomen, rapid weight loss, loss of appetite, increased thirst, late malnutrition, dehydration and death. Autopsy showed catarrhal hemorrhagic enteritis in the large intestine; intestinal wall swelling, thickening, mucosal congestion, bleeding, thin intestinal contents, dark red mixed with blood; some necrotizing inflammation, with caseous pseudomembrane. Clinical diagnosis is generally collected fresh feces, smears, stained with crystal violet, microscopic examination, each visual field can see more than 5 slender curved, sharp spirochetes at both ends. If the dark field microscopic examination of fresh diseased feces, you can see the lively movement of large spirochetes.