into the winter, the weather becomes cold, pigs are prone to diarrhea phenomenon, the following to introduce the winter common three kinds of viral diarrhea, and hope to help you pig production.
1. infectious gastroenteritis
is caused by coronavirus transmissible gastroenteritis virus is an acute and highly contagious disease in the digestive tract of pigs of all ages infection, vomiting, diarrhea and dehydration characteristics about its age, the degree of harm and disease of swine maternal antibody status and epidemic intensity, generally within 10 days old piglets there is high mortality, over 5 weeks old pigs rarely death.
the main source of infection is the virus after the recovery of poisoned pigs. the virus mainly exists in porcine intestinal mucosa, intestinal contents, mesenteric lymph nodes and tonsils, and with faeces for 8 weeks. the main route of transmission of the disease is through ingestion of contaminated feed, through the digestive tract infection; can also be infected through respiratory tract. especially in closed pig, humidity, pig farms concentrated more easily spread. the prevalence of the disease is that the disease occurs in the cold winter and winter months, that is, between november and april. once it occurs, it spreads quickly in pigs and can infect most pigs in a few days. in the old endemic area, endemic or intermittent endemic occurs frequently, which is usually confined to piglets aged 6 days to 2 weeks after weaning, and the morbidity and mortality are lower than those in the new endemic areas.
suckling piglets often vomit after feeding, followed by rapid watery diarrhea. the stools are yellow green or grayish white. later, they are slightly gray brown and contain curds. in some cases, the temperature of the pigs increased at first, and the body temperature decreased after diarrhea. sickness pig is dispirited, is rough, does not have the luster, shivers, the breast feeding, reduces or stops the feeding, the serious thirst, the rapid dehydration, soon loses weight, finally dies because of exhaustion. within the 10 day old piglets have a higher mortality rate, with the increase of age and death rate decreased, the growth of piglets was relatively slow, often become stiff pig. pigs and adult pigs feeder pigs, high incidence of sudden watery diarrhea, stool was gray or gray brown, less food, a few days to the weak, rapid weight loss, sometimes vomiting, fever, severe diarrhea, lactation to reduce or stop. generally 3-7 days to recover, rarely die. pregnant sows and adult male sows often do not develop after infection, and only a small number of patients with watery diarrhea or transient soft stools.
the main lesions are in the stomach and small intestine. piglet gastrointestinal expansion, stomach filled with undigested curds, gastric mucosal hyperemia, and sometimes bleeding spots in the mucosa. the small intestine is full of yellow, green, or gray liquid containing foam and undigested small lumps of milk. the walls of the small intestine become thinner and the elasticity is lowered so that the intestine expands and is translucent. mesenteric vascular dilatation, lymph node swelling, mesenteric lymph vessels can not see the presence of chyluria. the jejunum was cut longitudinally, and the contents of the intestine were washed out with normal saline, and a small amount of saline was added to the glass plate. at the low magnification microscope or under the magnifying glass, the villus of jejunum was significantly shortened. histologically, mucosal epithelial cells were denatured and exfoliated. the kidney is usually cloudy, swollen and fatty, with white urate deposits. some suffer from pneumonia.
2. porcine epidemic diarrhea
is an acute intestinal infectious disease caused by porcine epidemic diarrhea virus in pigs, with watery diarrhea, vomiting and dehydration characteristics. commonly known as winter diarrhea disease. the pathogeny is a genus of coronavirus. it is sensitive to ether, chloroform and so on, and has little resistance to external environment and disinfectant. a general disinfectant can inactivate it.
the disease has a certain season, often born in winter, december to february next year, winter season, summer can also occur, pigs of all ages can be infected with the disease. the incidence of infection in suckling piglets, weaned piglets and finishing pigs was 100%, and that of adult sows ranged from 15% to 19%. piglets were most seriously injured, with an average fatality rate of 50%. different from tge, ped spread slowly, often in 4~5 weeks throughout the entire pig farm, the mortality rate is not high, there is a certain self limiting, after 1 months or so popular stop.
the sick pigs showed vomiting, diarrhea, and dehydration. at the beginning of rows of yellow viscous diarrhea, became watery diarrhea, vomiting, accompanied by depression, anorexia, weight loss and failure. the smaller the age, the more severe the symptoms were, and within 1 weeks the suckling piglets died within 2~4 days of diarrhea, with a mortality rate of 50%. weaned pigs, pigs mild symptoms, diarrhea, loss of appetite, depression, lasting 4 to 7 days, gradually returned to normal.
the necropsy showed emaciation and dark grey skin. subcutaneous adipose tissue showed poor performance. the intestine expands and expands, filled with yellow fluid, thinning of the intestinal wall, congestion of the mesentery, and swelling of the mesenteric lymph nodes. microscopically, villus shortening was seen in the small intestine, with concentrated epithelial nuclei and eosinophilic cytoplasm. when the diarrhea was severe, the villus length to crypt ratio decreased from normal 1:1 to 3:1.
3. porcine rotavirus disease
it is an acute gastrointestinal infection caused by rotavirus (rv) in piglets. characterized by diarrhea at the clinic. adult pigs are generally infected with a recessive infection. rotavirus is an infectious disease of human beings and animals. it can infect humans and many livestock and poultry. it has high infection rate and high incidence, which is harmful to human health and animal husbandry.
rotavirus belongs to the genus reovirus. insensitive to ether and chloroform. can withstand ph3 ~ 9. in faeces, 60 30min survived and could survive for 7 months at room temperature |
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