Diagnosis and prevention of porcine erysipelas

First, popular characteristics. The disease mostly occurs in 2-6-month-old shelf pigs. Diseased pigs and infected pigs are the main sources of infection of the disease. The main route of infection is the digestive tract, and it can also be transmitted through skin wounds, or by blood-sucking insects such as mosquitoes and flies. The disease can occur all the year round.

Second, symptoms and pathological changes. The disease can be divided into acute type, subacute type and chronic type.

Acute type: that is, septic type, the body temperature of diseased pigs suddenly rises to more than 42 ℃, does not eat, gait is unstable and even cannot afford to lie on the ground. Conjunctival congestion, bright eyes. Erythema appears on the medial skin of chest, abdomen and thigh, finger pressure is easy to fade, and then return to red. The course of the disease is short, sudden death, the mortality rate is 80-90%, or become rash type or chronic type. When suckling piglets and newly weaned pigs occur swine erysipelas, they generally have sudden onset, neurological symptoms, convulsions and fall to the ground and die, and the course of the disease is generally no more than 1 day.

Subacute type: body temperature rises to about 41 ℃ at the beginning of the disease, loss of appetite and constipation. 2-3 days later, a clearly defined rash appeared in the chest, abdomen, shoulder, back and limbs, with square, diamond or quasi-round, slightly protruding from the surface of the skin, about a few centimeters in diameter. The touch is hard, the light ones fade after several days, recover on their own, and the heavy ones form brownish-red crusts that remain unchanged for a long time. Some become septic or chronic. The course of the disease was 1-2 weeks, and the mortality was low.

Chronic type: inflammation, swelling and claudication of the joints of the limbs of sick pigs; endocarditis of pigs with dyspnea, visible mucosal cyanosis, weak physique, slow growth, long course of disease and less death. The fibrinous exudate was found in the articular cavity and cauliflower-like vegetation could be seen on the surface of the heart valve.

Third, diagnosis. A preliminary diagnosis can be made according to epidemic characteristics, clinical symptoms and changes of autopsy. Those with atypical symptoms need to be examined in the laboratory.

IV. Prevention and control measures

1. Preventive vaccination: ⑴ inactivated porcine erysipelas vaccine: inactivated aluminum hydroxide vaccine was injected subcutaneously or intramuscularly, and the immunization period was 6-8 months. ⑵ live attenuated porcine erysipelas vaccine: use GC42 attenuated vaccine to add 20% aluminum glue saline 1 ml dissolved according to the bottle label, subcutaneously inject 1 ml, take orally 2 ml per head, and the immunity period is 6 months. ⑶ injection of swine fever, swine erysipelas, porcine pneumoconiosis triple live vaccine or porcine erysipelas and porcine pneumoconiosis aluminum hydroxide double inactivated vaccine, the immune effect is the same as the single vaccine.

2. Drug treatment: ⑴ amoxicillin powder injection was given intramuscularly 15 mg per kilogram of body weight, 1-2 times a day for 2-3 days. ⑵ penicillin was injected intramuscularly with 20 000 units per kilogram of body weight twice a day for 2-3 days. The efficacy of ⑶ cephalosporin powder injection can be maintained for 9 days by intramuscular injection of 20 000 units per kilogram of body weight. ⑷ 10% sulfadiazine sodium injection, 20-40 ml intramuscular injection per head per day, 1-2 times a day. ⑸ anti-swine erysipelas serum has a good curative effect.

3. Strengthen feeding management: ⑴ should do a good job in pigsty and environmental hygiene and disinfect it regularly. ⑵ does not import pigs from epidemic areas. Newly purchased pigs must be isolated and observed for 2-4 weeks before healthy people can enter the herd. ⑶ has a strict quarantine system to prevent all poisonous animals and pollutants from entering pigs.