Porcine contagious pleuropneumonia is a serious respiratory infectious disease caused by Actinobacillus pleuropneumoniae. The virus strain * * shares serotype 15, and the main serotypes prevalent in China are 1, 3, 5 and 7. The disease mostly occurs in large pig farms in winter, and piglets aged 3 ~ 6 weeks are most susceptible to infection.

Acute dyspnea in pigs is characterized by mouth opening and tongue spitting, dog sitting posture, foam-like reddish secretion in mouth and nose, and deep purple skin in mouth, nose, ears and limbs. Subacute pigs have no fever, intermittent cough, loss of appetite and decreased weight gain.

Because the cross-immunity between different serotype strains is not strong, it is necessary to select vaccines for local prevalent serotypes to make strains, and vaccinate sows and pigs aged 2 ~ 3 months to effectively control the occurrence of pleuropneumonia.