Haematology, bronchoalveolar cellular changes and pathology of swine pneumonia in Nigeria

Abstract

Respiratory diseases are of considerable economic importance in pigs, and less emphasis is on the diagnostic approaches in porcine health in our environment. The aim of this study was to compare the diagnostic accuracy of haematology, gross, bronchoalveolar lavage (BAL) and histopathological changes of pneumonia in  pigs. The study was conducted at a municipal abattoir for over  three months. A total of 146 finished pigs were clinically  examined. Blood samples were taken, while the plucks were  examined for lung lesions. Lavage samples and lung sections were taken for BAL and histological examinations. Six breeds were  slaughtered comprising Large White 112 (76.7%), Mixed Breed 15 (10.3%), Duroc 7 (4.8%), Local 6 (4.1%), Hampshire 4 (2.7%), and Large Black 2 (1.4%). Based on sex, 71 (48.6%) were males while, 75 (51.4%) were female. Grossly, there was pneumonia in 92 (63.0%) of the pigs and the mean pulmonary consolidation score was 9.6±1.2. The large white breed had the highest  consolidation score. Also, the right and left caudal lobes had the highest consolidation scores. Clinically, there was mild anaemia and leukocytosis, and BAL fluid cellular differential showed increased lymphocytic and neutrophilic counts in the pigs with pneumonia (p<0.05). Histologically, 91 (62.2%) of samples were normal, bronchointerstitial pneumonia was 31 (21.4%), bronchopneumonia was 18 (12.4%), granulomatous pneumonia was 1 (0.7%), bronchiolitis was 4 (2.7%), and verminous  pneumonia was 1 (0.7%). Bronchointerstitial pneumonia was the most prevalent pattern. Porcine pneumonia is still important in our environment; the roles of different causal agents need to be elucidated for production of vaccines and control in Nigeria and other parts of West Africa.

Keywords: Bronchoalveolar lavage, Cytology, Swine,   Pneumonia, Diagnostics