Clinical diagnosis and treatment of Porcine Influenza

Swine influenza is an acute, febrile and highly contagious disease caused by influenza A virus. The occurrence of the disease can lead to the death of diseased pigs and slow growth rate, which brings huge economic losses to the industry. In July 2004, an infectious disease characterized by persistent high fever and a series of respiratory diseases occurred in a large-scale pig farm in our city. Through on-the-spot inquiry, clinical observation, pathological anatomy and other comprehensive diagnostic measures, the preliminary diagnosis of swine influenza.

1 morbidity

The pig farm has superior geographical location and reasonable layout. A total of 350 live pigs were stored, including 16 binary sows, 124 suckling piglets and 210 growing and growing pigs. All kinds of epidemic prevention are vaccinated according to routine vaccination. At the beginning of July, some growing and breeding pigs began to get sick, and spread rapidly and ferociously. By the middle of July, all growing and breeding pigs fell ill, and some suckling piglets also showed symptoms, with an incidence of 77.14% and a mortality rate of 7.28%. After the onset of the disease, penicillin, analgin and other drugs have been used, but the effects are not satisfactory.

2 clinical symptoms

The incubation period of the disease is short, ranging from a few hours to several days, and it spreads rapidly, and the whole herd of pigs is infected almost at the same time in about a week. The body temperature of diseased pigs rises to 40 ℃ 41 ℃, the highest is 42 ℃, loss of appetite or loss of appetite, depression of spirit, pain in muscles and joints, often lying on the ground, unwilling to move, forcing them to walk with lameness and screaming during capture. The diseased pig is short of breath, showing abdominal breathing, accompanied by paroxysmal and spasmodic cough. Mucous or purulent secretions flow from the eyes and nose, conjunctival congestion and redness, constipation and yellow urine.

3The change of dissection.

The autopsy of dead pigs showed that the main lesions were in the respiratory organs. The mucous membrane of nostril, trachea and bronchus is congested and swollen, with a large amount of foamy mucus on the surface, sometimes with blood. The bronchioles and bronchioles were filled with foamy exudates, and the lesions of the apical lobe, cardiac lobe and intermediate lobe were red to purple, collapsed, atrophied, solid, with obvious tissue boundaries, hilar lymph nodes, bronchial lymph nodes and cervical lymph nodes edema, extroversion and juicy; there are mucous and cellulosic exudates in the pleural cavity. Severe gastric mucosal congestion, macular congestion in the large intestine and slight splenomegaly.

4 diagnosis

According to the season and weather conditions, as well as the characteristics of sudden onset, rapid transmission, obvious respiratory symptoms, high morbidity and low mortality in pigs, combined with the changes of autopsy, a preliminary diagnosis can be made. If further identification of the pathogen is required, laboratory testing shall be carried out.

5 Prevention and control measures

At present, there is no effective vaccine to prevent the disease, so the prevention and treatment of the disease should take symptomatic treatment and control of secondary infection-based comprehensive prevention and treatment measures.

5.1 implement closed management of pig farms, establish, improve and strictly implement the veterinary health and epidemic prevention system, and prevent the introduction of foreign sources of epidemic. Strengthen feeding and management, isolate sick pigs immediately, close other pig houses, stop turnover, and disinfect pigs. Do not harass or move sick pigs during the onset of the disease, and provide adequate clean drinking water, which can alleviate symptoms and shorten the course of the disease.

5.2 adhere to the symptomatic treatment, according to the principle of "heat-clearing and detoxification, anti-inflammation and relieving defecation", Chinese herbal medicine fresh Reed root decoction was fed continuously for 5 days for 7 days, plantain, green leaves, Bupleurum, purple flower and other fresh or decoction were fed for 6 days for heat-clearing and detoxification. In the middle and later stages of the disease, glucose saline and clean succulent feed rich in vitamins and trace elements were fed to moisturize the intestines and defecate.

5.3 Control of secondary infection, drinking water with appropriate amount of antibiotics (such as florfenicol), intramuscular injection of compound aminopyrine and penicillin, or intramuscular injection of Banlangen injection, or long-acting oxytetracycline injection.

By taking the above comprehensive prevention and control measures, the disease was basically controlled after 5 days, and the pigs gradually returned to normal after 7 days.

6 summary and experience

6.1 Swine influenza is a zoonotic disease. During the epidemic, the spread of the virus should be avoided as far as possible, and the protection of breeders should be done at the same time. Swine influenza is susceptible to pigs of different ages, breeds and genders, and sick pigs and convalescent pigs are the main sources of infection. It is mainly transmitted through respiratory droplets, and contaminated feed and drinking water can also be transmitted indirectly. The disease usually occurs during the transition of spring and summer with sudden changes in climate and in cold winter, but when it is overcast and rainy, humid, muggy, crowded, malnourished and abrupt in feeding conditions, the decline of pig resistance also promotes the occurrence and prevalence of the disease.

6.2 to improve the conditions of feeding and management, in the season of changeable climate and the bad weather of overheating or cold, special attention should be paid to strengthening the feeding and management of pigs, keeping the pig house clean and hygienic, keeping warm in winter and preventing heat and cooling in summer. The breeding environment should be disinfected regularly and pigs should be dewormed regularly. Under the condition of intensive feeding, the feeding density should be reasonable to prevent the crowding of pigs. In order to carry out the large-scale field of ring feeding, it is necessary to change the traditional feeding habits and implement advanced and hygienic feeding and management methods.