Porcine endemic pneumonia, also known as porcine asthma, is a respiratory disease caused by Mycoplasma hyopneumoniae infection and characterized by lung lesions and damage. The disease has a long incubation period, so more pigs are infected without being detected, resulting in the disease being present in the herd. The disease has a high infection rate and a low mortality rate, but it can cause growth retardation and reduce the meat exchange rate, which will prolong the time to market and lead to an increase in the cost of pig rearing and a decrease in economic benefits, causing great losses to the pig industry.

The pathogen of porcine pneumonic disease is bacillus bacillus main symptoms are body temperature rises 40-41 degrees initial spasmodic dry cough, breathing difficulties, sometimes nasal fluid mixed with blood, and then become wet cough, coughing pain, palpation with severe pain, auscultation has a roaring, and friction sound, the development of the disease, breathing is more difficult, open-mouthed spit tongue, canine sitting, visible mucous membranes cyanosis, often with purulent conjunctivitis; the first constipation or diarrhea, the skin bleeding or small blood spots; lying on the floor. Skin hemorrhages or small blood spots; lying down for about 5 days to become chronic