Evaluation of Lung Lesions and Associated Predisposing Factors from Slaughtered Pigs in Nigeria

Abstract

Pigs are prolific and fast growing livestock but certain factors limit its production in Nigeria. The incidence, and pattern of pneumonia, its associated predisposing and risk factors were studied in pigs slaughtered at the major Municipal abattoirs in southwest Nigeria. Pigs weighing 80-160kg body weight were examined for over three months at abattoirs. The age, sex and breed of the animals were noted. Gross visual appraisal of pneumonic lesions was made as percentage of lung tissue affected while lung samples were processed routinely for detailed histological examination. A total of 250 pigs were clinically examined. Males comprise 19.4% and females 80.6%. The breeds slaughtered include large white (85.5%), large black (6.5%) and Duroc cross (8%). 90 pigs were randomly sampled for the morphometric and pathological evaluations, out of which 62 were pneumonic. The large white breed had the highest lung consolidation score (11) as compared to large black (9.7) and duroc (9.0). The mean consolidation score was also high in the female and the right lobes had lung consolidation scores more than left lobes. The histologic patterns of pneumonia include congestion and oedema (9%), atelectasis (3%), fibrinous (17%) and suppurative bronchopneumonia (2%), broncho-interstitial pneumonia (32%), verminous pneumonia (2%) and granulomatous pneumonia (4%) and normal (31%). The male pigs were more predisposed to pneumonia, and breed is a major risk factor to pneumonia in this environment. There is need for strict implementation of control measures on curbing porcine pneumonia.