Bacterial Disease of Pigs-Bacillus anthracis

Anthrax is an acute septic infectious disease caused by Bacillus anthracis in livestock, wild animals and human beings. The clinical symptoms were septicemia, and the autopsy changes included poor blood coagulation, significant splenomegaly and hemorrhagic colloid infiltration under the skin and serosa. Pigs are sporadic, mostly subacute or chronic.

Epidemic characteristics: Bacillus anthracis forms spores and can survive in the external environment for a long time. Pigs are infected through the digestive tract and grazing pigs can be infected by looking for food through arched soil. Pigs are less susceptible; they are mostly found during sporadic or slaughtering; they occur a little more in summer.

Most of the clinical symptoms of pigs are chronic, there are no obvious clinical symptoms, and most of them are found in the meat test after slaughtering; some pigs (subacute type) are symptoms of pharyngitis, elevated body temperature, loss of spirit and appetite, obvious swelling of throat and parotid glands, dysphagia and dyspnea, inflexible neck movement, cyanosis of oral and nasal mucosa, and finally suffocation death; individual pigs may also have symptoms of acute septicemia.

Pathological changes in order to prevent the spread of pathogens and cause new foci, dissection is prohibited when anthrax is suspected. In pigs with acute septicemia, rapid corruption, incomplete rigor, dark purple mucosa, red or red-yellow colloid infiltration in subcutaneous, muscle and serosa, and bleeding spots can be seen; poor blood coagulation, as thick as coal tar; spleen is highly enlarged and soft, the splenic pulp is soft as mud, dark red; lymph node enlargement, bleeding; heart, liver, kidney degeneration; gastrointestinal hemorrhagic inflammation. Pharyngeal anthrax showed tonsil necrosis, inflammatory edema in larynx, pharynx and neck, swelling, bleeding and necrosis of turnover lymph nodes. The characteristic changes of chronic anthrax after slaughter of pigs are as follows: inflammation of pharynx, enlargement and necrosis of tonsils, swelling, bleeding and necrosis of submandibular lymph nodes, dry section, no luster, brick-red, gray or grayish-yellow necrotic foci, and yellow-red infiltration in turnover tissue.

The peripheral blood or spleen of suspected dead pigs were smeared and stained with anthrax capsule (formaldehyde gentian violet or methylene blue staining). The characteristic colonies of Bacillus anthracis could be seen in isolation and culture.

When pig anthrax seriously pollutes pig farms, consider using 0.5 ml of non-toxic anthrax spore vaccine or 1 ml of No. 2 anthrax spore vaccine, subcutaneously injected, two weeks after injection to produce immunity, the immune period is one year. Once the disease occurs, immediately treat the disease with anti-anthrax serum 50-100ml (pigs) and antibiotics (penicillin, tetracycline, etc.) or sulfonamides, report the epidemic situation at the same time, and take resolute measures to block, isolate, disinfect and destroy the body to extinguish the epidemic as soon as possible.

Slaughterhouses and meat factories should strengthen the quarantine of slaughtered pigs, especially the head quarantine after bloodletting.