Prevention and treatment of several new diseases in pigs

1. Post-weaning multi-system emaciation syndrome

The disease is a new disease characterized by shortness of breath or dyspnea, diarrhea, anemia, obvious lymphoid lesions and progressive weight loss in weaned pigs caused by porcine circovirus Ⅱ (PCV2). The incidence of the disease is 5% to 20%, some as high as 100%, and the mortality rate is 100%. It has seriously affected the growth and development of pigs, caused huge economic losses, and has evolved into a worldwide disease, which has been widely concerned by countries all over the world.

The disease mostly occurs in pigs aged from 6 weeks to 9 weeks. The clinical manifestations are progressive weight loss, shortness of breath or difficulty, cough, sometimes diarrhea, pallor and jaundice. Autopsy shows enlarged lymph nodes, but no bleeding, rubber-colored lungs and enlarged waxy kidneys. White spots can be seen on the surface of the kidney. Microscopic changes, emptying of lymphoid follicles, granulomatosis of lymph nodes, liver and other tissues, and lymphoid tissue interstitial pneumonia in the lungs. Because the clinical symptoms are not specific, the diagnosis can only be confirmed by laboratory examination of PCV2 antigen or nucleic acid.

In the prevention and treatment of the disease, in addition to introducing healthy pigs, doing a good job in feeding and management, reducing stress factors, strengthening quarantine and disinfection and other measures, the best way to carry out immune injection. PCV2 vaccine has been available, and immunization can effectively prevent the disease. In treatment, Inmodulen is a newly developed biological immune therapy, which can significantly reduce mortality.

Haemophilus parasuis

Haemophilus parasuis is a new infectious disease of porcine polyseritis, arthritis and meningitis caused by Haemophilus parasuis. The disease is easy to occur under stress conditions, such as changing material, changing group, changing temperature, immunity, castration and so on. the disease is very widespread, and the pathogen is mainly found in all countries. In recent years, due to a large number of frequent introduction from abroad, the disease has been brought into our country, and began to occur in some areas, we should be highly vigilant.

Symptoms: characterized by cough, dyspnea, emaciation and rough coat. The main manifestations are fever, loss of appetite, anorexia, dyspnea, joint swelling, lameness, trembling, slow response, ataxia, cyanosis of visual mucosa, cyanosis of ear tip and blue abdomen; acute cases of weaned piglets, subcutaneous and pulmonary edema, death soon after the emergence of stress or neurological symptoms; acute infection in sows with abortion; lameness in boars.

Autopsy: multiple serous and suppurative fibrin exudation, multiple sites in the peritoneum, cardiac membrane and pleura, sometimes in the meninges and joint surfaces, especially in the wrist and tarsal joints; bleeding spots can be seen occasionally on the renal surface.

Prevention and treatment: immunization with inactivated Haemophilus parasuis vaccine can effectively prevent the disease. Once the disease is treated with penicillins or cephalosporins, for the group, in addition to individual focus treatment, the whole group administration can effectively control the epidemic of the disease.

Porcine proliferative bowel disease

Porcine proliferative enteropathy, also known as proliferative ileitis, is an infectious disease of adenomatous hyperplasia of glandular fossa epithelial cells of porcine small intestinal mucosa caused by intracellular Lawsonella. In recent years, the incidence of the disease is on the rise in the United States, Australia, Brazil, France, Denmark, Britain and other countries, so it has been paid more and more attention.

The clinical feature of the disease is tar diarrhea, which often occurs in growing pigs from 6 weeks to 20 weeks old, and sometimes in nursing piglets and adult boars and sows. The autopsy eyes mainly included proliferative bowel disease, bleeding, diffuse necrotizing cecal colitis, similar to porcine dysentery. Laboratory diagnosis can be made by microscopic examination combined with PCK and specific high immune rabbit serum or monoclonal antibody fluorescence immunoassay to detect bacteria in feces.

The disease can be effectively controlled by vaccination breeding group and weaning fattening group. Lactation sows and reserve sows can also be mixed with lincomycin and spectinomycin for 8 weeks, which can effectively prevent and cure the disease. Once the disease occurs, intravenous injection of erythromycin can be effective quickly.

Porcine dermatitis and nephrotic syndrome

The disease mainly affects pigs aged from 8 weeks to 18 weeks, with an incidence of 12%-30% and a fatality rate of 5%-14%. Clinical manifestations on the skin of chest, abdomen, thigh and forelegs, there are a wide range of purplish red round or irregular lesions of different sizes and shapes, which may be fused; sick pigs show anorexia, depression and fever of about 41 ℃, and 60% / 80% of pigs with skin lesions die. Autopsy showed kidney enlargement, pallor, focus, gorgeous, sometimes bleeding and edema; lymph node enlargement, bleeding, ileocecal buckle ulcer, pulmonary edema or rubber-like, occasionally gastric ulcer and colitis. Pay attention to the identification of the disease with classical swine fever and swine erysipelas to avoid misdiagnosis.

There is no specific prevention and immunity for the prevention and treatment of the disease, and there is no specific drug to treat it. The control of the disease is based on good management and high-level biosafety measures, as well as all-in-all-out and effective disinfection measures to achieve the purpose of prevention and treatment.

5. Swine hepatitis E

Swine hepatitis E is one of the emerging zoonotic diseases that have attracted much attention. Hepatitis E virus (SHEV) is the main cause of human viral hepatitis. The incidence of fulminant hepatitis is higher in young adults, with a mortality rate of 0.5% to 3%, but the mortality rate in pregnant women can be as high as 15% to 20%.

Early weaning (17 ~ 19 days old) can be taken to prevent the disease in pigs, which can prevent vertical transmission, and strict isolation of piglets can prevent horizontal transmission. These measures are helpful to establish virus-free pig samples. For people in hepatitis E endemic areas, effectively improving water quality and boiling water before drinking will be the key to control the spread of the disease, because the virus mainly spreads through contaminated water sources.

VI. Pig blue eye disease

Porcine blue eye disease is a new disease of pigs caused by porcine mumps virus. The disease mainly infects boars. After infection, boars show enlargement of testis and epididymis, serious changes in sperm, decrease of sperm concentration, weakening of sperm acrosome damage activity, and virus in semen, which can be detoxified through semen. The disease is easily confused with porcine Japanese encephalitis and should be distinguished. The virus can be detected in the semen of infected boars by indirect immunofluorescence test.

The best way to prevent and cure the disease is to be vaccinated. Mexico's commercial inactivated vaccine against porcine blue-eye disease has been available and can be used for emergency preventive injections.