Introduction to the causes and Prevention techniques of Asthma in Pigs

Pig farm

Porcine asthma or porcine asthma, also known as Mycoplasma pneumoniae, is a chronic respiratory infectious disease of pigs. The main clinical symptoms of the disease are cough and asthma, and the pathological changes are mainly located in the chest. The lungs are the main organs of the disease. The acute cases were mainly pulmonary edema and emphysema, and the "shrimp meat" consolidation of the lungs was seen in subacute and chronic cases. The growth rate of diseased pigs was slow, the feed utilization rate was low, and the fattening period was prolonged.

Pathogen and epidemic of Asthma in Swine

Pneumoplasma pneumoniae is one of the three main pathogens causing respiratory diseases in pigs, and the detection rate is about 19% in cases of respiratory diseases in pigs.

Mycoplasma hyopneumoniae mainly exists in respiratory tract, lung tissue, hilar lymph nodes and mediastinal lymph nodes of infected pigs. Diseased pigs and infected pigs are the main sources of infection. The main routes of transmission are respiratory tract transmission, direct contact transmission and droplet transmission, and the pathogens only infect pigs; at the initial stage of infection, Mycoplasma hyopneumoniae exists on the surface of trachea and bronchus, and damages the mucociliary barrier, which makes the proliferation of lymphoid cells around bronchi and blood vessels; the immune response of infected pigs to Mycoplasma hyopneumoniae mainly occurs in the later stage of the disease, which shows that this infection has a certain immunosuppressive effect.

The incidence of the disease has no difference in variety, age and sex, it can occur throughout the year, and it is more common when it is cold, rainy, humid or sudden climate change. Poor feed quality, overcrowding, dampness and poor ventilation are the main causes. The mortality rate is not high when infected alone, but once the pigs are introduced, it is difficult to eliminate them completely if no strict measures are taken.

In the case of natural infection, it is easy to be secondary to Pasteurella multocida, pneumococci, Actinobacillus pleuropneumoniae, Salmonella and various suppurative bacteria, Mycoplasma suis and Chlamydia granulosa, etc., resulting in aggravation of the disease and increased mortality.

Pig farm

Prevention and treatment of Asthma in Pigs

1. Improving air quality is the key to the prevention and treatment of this disease.

Porcine asthma can only be in direct contact with healthy pigs through diseased pigs. Secretions containing pathogens can be ejected from diseased pigs by coughing, wheezing and sneezing to form droplets, which can not be infected by wound, subcutaneous injection and digestive tract infection. Because of the occurrence of infectious diseases, disease can only be caused by infection with a certain number of pathogens. For diseases transmitted by air droplets, by increasing ventilation, the concentration of pathogens in pig pens can be reduced and the occurrence and spread of the disease can be controlled.

2. Carry out vaccination

Vaccination is an important means to control the occurrence of infectious diseases. It is suggested that vaccination should be carried out in farms with frequent occurrence of porcine asthma, and adult breeder pigs should be immunized with attenuated porcine asthma virus freeze-dried vaccine once a year; backup breeder pigs should be vaccinated once before breeding; piglets should be vaccinated once at the age of 7 and 15 days. Infected pigs can be injected intraperitoneally with porcine asthma rabbit lyophilized vaccine, and antibiotics should not be injected as far as possible after injection. However, the feedback information after the use of the vaccine shows that there are many failures of vaccine immunization, and there are still a small number of local diseases after immunization. The occurrence of immune control of porcine asthma vaccine is a worldwide problem. The immune protection rate of porcine asthma vaccine has been improved in recent years, but it still can not avoid the occurrence of local minority.

3. Antibiotic treatment

Mycoplasma suis is not sensitive to penicillin and sulfonamides, but sensitive to spectinomycin, oxytetracycline and kanamycin.

The sick pig farms can be treated by adding 200 grams of lincomycin per ton of feed for 21 days. Kanamycin sulfate was injected intramuscularly twice a day for 5 days with 10~20mg per kg body weight. Oxytetracycline hydrochloride per kg body weight 30~40mg, diluted with 0.25% procaine injection or 4% borax solution, was injected intramuscularly once a day for 7 days. 0.05% oxytetracycline was mixed and fed for 5 to 7 days, while kanamycin was injected intramuscularly at a rate of 20,000 to 40,000 units per kilogram of body weight, once a day for 3 to 5 days. Tylosone injection was injected intramuscularly with 0.4ml per kilogram of body weight twice a day.

4. prophylactic administration in high incidence season

According to the epidemic characteristics of porcine asthma in this field, preventive medicine can be given in advance in the frequent season of porcine asthma. Piglets can be fed with 400g terramycin 800g per ton diet during the changing season or weaning period, and 0.5ml was injected intramuscularly at 2, 7 and 21 days old to get long-acting injection.

5. Strengthen feeding and management.

Strengthen scientific management and create a good growth environment. Strengthen protection against cold and warmth in winter and spring, prevent heat and cool down in summer and autumn, and reduce the stimulation of various adverse factors.

If the feeding density is reduced, generally speaking, if the feeding density is doubled, the incidence of infectious diseases will increase tenfold. The reduction of feeding density is also an important means to control the spread of the disease. Pay attention to environmental disinfection, disinfect the pig house once or twice according to the epidemic situation, and the incidental pathogenic microorganisms in feces and dirty water should be treated innocuously. The commonly used disinfection drugs are 0.5% formalin, 0.5% caustic soda, 20% lime milk, 1% carbonic acid, etc., scientific preparation of diets, reasonable matching with each other. Make sure you don't add more often. Strengthen ventilation, keep piggery dry, reduce ammonia stimulation, reduce dust, dust carrying a large number of pathogenic microorganisms.

6. Establish a healthy breeding pig herd without pathogens.

For the conditional pig breeding farms, quarantine and purification can be carried out to establish breeding pig herds that do not carry the pathogen of porcine mycoplasma. Areas or pig farms without this disease shall carry out the principle of self-reproduction and self-support. Introduction should be strictly quarantined and strictly implement various veterinary epidemic prevention systems, which can put an end to the introduction of pathogens.

Purification work can be carried out for pigs with disease or pathogenic infection of porcine asthma. At present, there are many detection methods of porcine asthma, simple operation and high sensitivity. There are porcine asthma hemagglutination test and porcine asthma-ELISA test are easy to be carried out at the grass-roots level. For breeding pigs with negative detection, after many times of purification and removal of infected pigs, positive pigs are eliminated, and healthy pigs without porcine mycoplasma pathogens are established.