Diagnosis, treatment and Prevention of Blue ear Disease in Pig breeding

Porcine blue ear disease, also known as porcine reproductive and respiratory syndrome (PRRS), is caused by porcine reproductive and respiratory syndrome virus in the arteritis family. The harmful form of the disease changed from reproductive disorders in sows to respiratory syndrome in nursing pigs. The disease was introduced into China from abroad and seriously affected the infectious diseases of the industry. The clinical symptoms were characterized by reproductive disorders, dyspnea, blue-purple ears and other infectious diseases. At present, the disease has new clinical symptoms, such as eyelid edema, subcutaneous edema, ear skin thickening, strange itching of mouth and nose, diarrhea, muscle tremor, ataxia, hindquarters paralysis and so on. Due to the large temperature difference and abnormal climate in spring and winter, the disease is caused, and there is no specific treatment at present, so it is very necessary to prevent the disease.

Popular characteristics

Porcine blue ear disease usually has no obvious seasonality, but its incidence is high in winter and spring. The main route of transmission of the disease is respiratory tract. Sick pigs and infected pigs can detoxify the air and pollute the surrounding environment. If disinfection measures are not in place, the virus can exist in pig houses for a long time. Sudden changes in climate and the introduction of pigs are often the causes of the disease.

Clinical characteristics.

1. Sows are divided into two types: acute and chronic.

Acute infection: persistent high fever, lethargy, body temperature 40 / 41.5 ℃, heartbeat fast (130 / 160 / min), dyspnea (30 / 60 / min), cough, asthma, dry stool with mucous blood, rapid infection. Pregnant sows were treated with antibiotics with little effect. When the sow's body temperature dropped, abortion began in 3-5 days, the symptoms of dyspnea were slightly alleviated, and the rate of stillbirth and mummified fetus was up to 20.25%. The incidence of postpartum piglets was high and the survival rate was low.

Chronic infection: poor physique of pigs, pale mucous membrane, jaundice, emaciation, cough, partial abdominal breathing, delayed estrus or repeated mismatch. With the prolongation of the disease, cyanosis in the limbs and ears of pigs appears blue-purple, starting from the ears and shoulders, gradually spreading discoloration all over the body. Lactation of lactating sows decreased, or even no milk, accelerated the death of piglets, especially within one week after delivery, the mortality rate increased significantly, up to 40-80%. If the nursing care is not strengthened, it can lead to aggravation and death of sows.

2. Shelf pig

Clinical manifestations include mild influenza symptoms, anorexia, depression and anemia. 4-5 days, mild jaundice, body temperature above 41 ℃, late cough and asthma, cyanosis of limbs, bluish-purple plaques on the back edge and tail of both ears, the incidence was about 10%, the mortality rate was about 50%, and the mortality rate was the highest in 7-10 days.

3. Boar

The incidence is low (2%-10%) and anorexia. Faster breathing, longer course of disease, partial paralysis, cyanosis of limbs and lower abdominal skin, blue-purple all over the body, local edema, especially in joints and buttocks, low sperm density, decreased motility and low mortality in adult boars. Paralyzed pigs are often secondary to streptococcal mixed infection, the disease is aggravated.

4. Piglets

The disease is often severe, newborn piglets with anemia, mild jaundice, fever, huddling, diarrhea, the highest mortality rate can be up to 85%. With the development of the disease, the skin of piglets changed from pale to slightly yellow-stained, blue and cyanotic in the later stage, especially in chest and abdomen, dyspnea, cough and asthma, odd itching in mouth and nose, stiff piglets in 6-week-old weaned pigs and growth retardation.

Pathological changes

The skin is as light as wax, and there is foam in the nostrils; the trachea and bronchi are full of foam, visible mucosal pallor, common eyelid edema in piglets and breeding pigs, yellow staining all over the body, subcutaneous edema, and a large amount of clear fluid in the chest of stillborn fetuses; piglets who died within 1 month, there are generally gray liver lesions on the edge of the anterior lobe of the lung; tracheotomy, the interior is full of foam Hilar lymph node enlargement, pulmonary interstitial enlargement, exudative pneumonia or lobar pneumonia in some pigs; hepatomegaly and degeneration, brown, systemic lymph node enlargement, section with bleeding spots; kidney pale, swollen, with uneven gray-white necrotic focus on the surface, splenomegaly and softening, thin colon contents; renal capsule is easy to peel off, there are needle tip bleeding spots on the surface. Piglets had subcutaneous edema, enlarged body surface lymph nodes, endocardial congestion and pericardial effusion edema.

Prevention and cure measures

At present, there is no specific treatment for porcine blue ear disease.

1. As the disease is often secondary to classical swine fever, porcine infectious pleuropneumonia, swine lung disease, porcine eperythrozoon and other diseases, no matter single infection or mixed infection, enclosure disinfection, strengthening feeding and reducing stress are important links. Simple control can not achieve the effect, only cooperate with prevention and control, strengthen feeding management, and often disinfect the enclosure. Once the pig farm is infected with blue ear disease, in addition to harmless treatment and enclosure disinfection of dead fetuses and dead pigs, sick pigs should also be fed with high-energy feed, multivitamins and adequate electrolytes, and sows should be fed with aspirin before giving birth. The following drug combinations can be added to piglet feed, such as Zhiyuanjing 100ppm + chlortetracycline 300ppm + amoxicillin 150ppm, which can be used continuously for 15 days after weaning, which can solve most of the problems of fattening pigs and prevent the disease of fattening pigs.

Echinacea detoxification needle can be used for 0.3ml per 1kg body weight for 3 to 5 days. When treating diseased pigs, antibiotics can be used to prevent secondary infection. At the same time, according to different secondary infection symptoms, it has a certain effect on the rehabilitation of diseased pigs.

2.Vaccine prophylaxis: 45kg reserve sows are recommended to use weak vaccine; sows are vaccinated with inactivated vaccine at 6 days after delivery and 60 days after mating; boars are first immunized 2-3 months before semen collection or mating, subcutaneously or muscularly flow to 2ml/ heads, once with the same dose after 20 days interval, and then once every 6 months; piglets: 1ml heads are injected subcutaneously or intramuscularly at 21 days of age.