The study was conducted to determine and characterize the macroscopic lesions present in pneumonic lungs of slaughtered pigs in San Mateo Municipal Slaughterhouse. Specifically, this was conducted to characterize and describe the gross morphology (color, consistency, distribution of lesion, exudation, pleurisy and adhesion) and to determine the prevalence of pneumonia based only on the gross morphological lesions. Data that were gathered from the mentioned parameters served as the basis in the etiologic diagnosis of pneumonia. The Systematic Random Sampling was used in the selection of pig lungs that was inspected and examined.

The result of this study showed that bronchial and interstitial pneumonia were the two most common classification that greatly affects those of the swine slaughtered. It also showed that the occurrence of pneumonia has a strong relationship with the macroscopic changes on the structure of the lungs especially in color (0.016), presence of Efferent exudate (<0.001), distribution of lesions (< 0.001) and a low relation in the changes of lung consistency (0.051). The lesions greatly influenced the occurrence of infection, and data from this study revealed that 83.3% (25) from the total lungs mined were positive with pneumonia. Majority of the lungs were affected with bronchial pneumonia which often caused by bacterial infection such as Mycoplasma hyopneumoniae, Haemophilus parasuis, Actinobacillus pleuropneumonia, etc. and interstitial pneumonia mainly caused by respiratory viruses such as Porcine Reproductive and Respiratory (PRRS) virus and/or Porcine circovirus.

In conclusion, swine pneumonia is highly prevalent in the slaughtered pigs at San Mateo Municipal Slaughterhouse (AA) implying the chances of not having a strict management practice among backyard raisers in reducing the development of different risk factors thus, resulting to the development of respiratory disease.

Thesis (Doctor of Veterinary Medicine)

includes appendix and bibliographical references.