Symptoms, Prevention and treatment of Porcine Blue ear Disease

Porcine blue ear disease was once called mysterious pig disease, new pig disease, porcine epidemic abortion and respiratory syndrome, porcine reproductive and respiratory syndrome, blue ear disease, swine plague, etc., porcine reproductive and respiratory disorder syndrome caused by virus, the rapid spread, the wide range of involvement, the high incidence and mortality rate is unprecedented. Let's take a look at the symptoms and treatment of porcine blue ear disease.

Acute type

The main manifestations of the diseased sows were depression, loss of appetite or abstinence, fever, dyspnea in varying degrees, abortion, premature delivery, stillbirth, mummified fetus and weak baby in the later stage of pregnancy (105-107 days). The abortion rate of sows can reach 50%-70%, the stillbirth rate can reach more than 35%, and mummies can reach 25%. Some newborn piglets show symptoms such as dyspnea, dyskinesia and paralysis, and the mortality rate increases significantly within 1 week after delivery (40%-80%). A few sows showed no milk after delivery, stagnation of placenta and increase of vaginal secretion.

One-month-old piglets showed typical respiratory symptoms, dyspnea, sometimes abdominal breathing, loss of appetite or abstinence, body temperature above 40 ℃ and diarrhea. Rough coat, ataxia, progressive emaciation, eyelid edema. A small number of piglets can see purple skin on their ears and body surface, and the mortality rate of piglets before weaning can reach 80%-100%. After weaning, the weight gain of piglets decreases, the daily gain decreases by 50%-75%, and the mortality increases (10%-25%). It has been resistant to slow growth of pigs and is prone to other diseases.

Growing pigs and fattening pigs showed mild clinical symptoms with different procedures of respiratory symptoms. A few cases showed cough and dark purple skin on the back, edge, abdomen and tail of both ears. Infected pigs are prone to secondary infection and corresponding symptoms.

The incidence of breeding boar is low, which is mainly manifested as general clinical symptoms, but the semen quality of boar decreases, sperm deformity, semen can be poisonous.

Chronic type

This is the main form of PRRS performance in large-scale pig farms at present. The main manifestations are the decline of the production performance of pigs, the slow growth, the decline of reproductive performance of sows, the decline of immune function of pigs, and easy to be infected with other bacterial and viral diseases. The incidence of respiratory diseases (such as mycoplasma infection, infectious pleuropneumonia, streptococcosis, eperythrozoonosis) increased in pigs.

Subclinical diagnosis type

The infected pigs did not get sick, which was characterized by persistent infection of PRRSV. The serological antibodies of pigs were positive, and the positive rate was generally 10% to 88%.

Prevention and cure measures

At present, there is no specific therapy for blue ear disease in pigs, and most measures are aimed at relieving acute symptoms, preventing secondary infection and reducing losses.

In the first month of onset of ①, aspirin and other drugs can be used to treat late pregnant pigs to reduce fever and prolong pregnancy. At the same time, sows were treated with antibiotics to prevent secondary infection.

② should be fed with high energy when the feed intake of pigs decreases.

In the acute stage of ③, the breeding of sows should be postponed, but more reserve pigs should be bred in order to reduce the decline in productivity. When the semen quality of boars decreases, artificial insemination should be strengthened.

④ ensures that weak piglets ingest human colostrum in time, and should postpone iron supplementation and tail amputation; give newborn piglets prophylactic antibiotics to prevent diarrhea; and prohibit foster care to avoid cross-contamination.

⑤ strengthens the prevention of pleuropneumonia, pseudorabies, streptococcus, asthma and other diseases in pigs, and increases the disease resistance of pigs.

⑥ added antibiotics to prevent secondary infection in growing pigs and supplemented with appropriate amounts of vitamin E and trace element selenium.

⑦ should maintain good sanitary conditions, strengthen environmental disinfection and clean the birth bed in time.

⑧ maintains a strict "full-in-all-out system", timely empty circle and fumigation to interrupt the circulation of the virus in the pig production process, and early isolation and weaning to prevent mixed feeding and infection.

⑨ should strengthen the management of reserve sows and postpone breeding of newly introduced reserve pigs in order to form natural adaptation.

For ⑩ positive pig farms, the freeze-dried vaccine of porcine blue-ear disease can be used to immunize reserve sows once before breeding, twice at an interval of 21 days. Sows that give birth to stillbirths due to blue ear disease do not need to be vaccinated within half a year. One sow can be vaccinated 21 days after parturition, and half of the piglets (7-21 days old) can be vaccinated. Boars are not vaccinated (for seriously polluted pig farms, sows can be vaccinated with inactivated vaccine against porcine blue ear disease in the middle and third trimester of pregnancy). For the pig blue ear disease negative pig farm, the inactivated pig blue ear disease vaccine can be used to immunize the reserve sows once before mating, twice at an interval of 21 days, and the sows can be vaccinated during the empty period, boars and piglets may not be vaccinated.