First of all, epidemiology:
This disease mainly occurs in pigs, and other animals and people can also be infected, which is called erysipelas. It can occur all year round, and it is frequent in hot and rainy seasons. Sick pigs and infected pigs are the sources of infection of the disease. It is mainly transmitted through digestive tract, skin injury and blood-sucking insects.
Second, clinical symptoms: the incubation period 1 day is short and 7 days long.
Acute type: common, listless, with a body temperature of 42-43℃, leading to sudden onset and high mortality. No eating, vomiting, conjunctival congestion, dry feces with mucus, diarrhea in the later stage of piglets. The skin on the ears, neck and back is red and purple. Before death, there were irregular bright red spots on armpits, thighs and abdomen, which fused after the finger pressure subsided. Often died in 3-4 days.
Subacute type (rash block type): the condition is mild. On 1-2 days, obvious, round, quadrilateral and feverish rash blocks appeared in different parts of the body, especially in the chest, back, neck and whole body, commonly known as "fire marks", indicating that the pressure subsided. Rash blocks protrude 2-3 mm from the skin, and the size is about 1 to several centimeters, ranging from several to dozens. After drying, brown scab skin is formed. Thirst, constipation, vomiting, high body temperature, many sick pigs died of sepsis during the onset. The course of disease is about 1-2 weeks.
Chronic type: it is transformed from acute type or subacute type, and there are also primary arthritis, common arthritis, joint swelling, deformation, pain, limping, rigidity and so on. Ulcerative or cauliflower-like verrucous endocarditis. Arrhythmia, dyspnea, anemia. The course of the disease is several weeks to several months.
Third, pathological changes.
Acute erysipelas is characterized by inflammatory edema of intestinal mucosa, severe gastric fundus and pylorus, small bleeding spots in the mucosa of small intestine, duodenum and ileum, erythema on the skin of body surface, swollen lymph nodes and congestion, cherry red or purplish red splenomegaly, soft texture, tight capsule, pure round edge, everted section, blurred structure of splenic trabecular and follicular cells. Needle-shaped bleeding spots and swelling can be seen on the surface and section of the kidney. Pericardial effusion, myocardial inflammatory changes, liver congestion, reddish brown. Pulmonary congestion and swelling.
Rash type: Rash is a special change.
Chronic type: ulcerative endocarditis, hyperplasia, gray cauliflower vegetation on mitral valve, valve thickening, pulmonary congestion, renal infarction, joint swelling and deformation.
Fourth, diagnosis
We can make a comprehensive diagnosis according to epidemiology, clinical symptoms and autopsy, and pay attention to the differential diagnosis with other diseases, especially swine fever, swine pneumonia, swine flu, toxoplasmosis and listeriosis.
When necessary, laboratory diagnosis is carried out, and the commonly used methods include direct smear microscopy, isolation and culture, animal test, whole blood plate agglutination test, etc.
Verb (abbreviation for verb) prevention and control
1, strengthen the management of feeding, farmers' market, slaughterhouse, transportation and quarantine, observe the purchased new pigs in isolation for 2 1 day, and disinfect pens and utensils regularly. Isolation, treatment and disinfection of epidemic situation. Inject penicillin into immunized pigs twice a day for 3-4 days to enhance immunity.
2. Preventive immunization: boars and sows are immunized with swine erysipelas aluminum hydroxide and formaldehyde vaccine twice a year in spring and autumn. When finishing pigs are 60 days old, they can be immunized once with erysipelas aluminum hydroxide formaldehyde vaccine or triple vaccine.
Step 3 deal with
Take the time to treat sick pigs.
(1) penicillin 1 10,000 units/kg body weight, or tetracycline 5000- 1 10,000 units/kg body weight or Kangdi injection 0. 1-0.2 ml/kg body weight twice a day.
② Intravenous injection of ampicillin or treatment with streptomycin or compound sulfadiazine sodium, lincomycin and tylosin.