Pathology and immunohistochemical evaluation of lungs of cattle slaughtered at metropolitan abattoirs in Nigeria and Ghana.

There was a dearth of information on pathology and causal agents of bovine pneumonia in West Africa. This cross-sectional study conducted at four major metropolitan abattoirs in Nigeria and Ghana was to evaluate the pathology and to immunohistochemically demonstrates viral and bacterial pathogens of bovine pneumonia in West Africa. Out of the 20,605 cattle lungs examined at post-mortem using standard inspection procedures, 136 samples grossly showed pneumonic lesions and 99 randomly selected lung samples were fixed in 10% neutral buffered formalin for histopathological and immunohistochemical examination. The overall prevalence of pneumonia was 0.66%, with 0.72% prevalence in Ibadan, Nigeria and 9.68% prevalence in Ghana. Age and breed were observed to be among the predisposing factors to pneumonia in cattle. Histologically, bronchopneumonia (0.65%), broncho-interstitial pneumonia (0.13%), and interstitial pneumonia (0.08%) were the prominent type of pneumonias observed. Immunohistochemically, 0.8% was positive for bovine PI-3, 0.9% for bovine RSV, 1.0% for (MH), and 0.6% for (PM). There were a few interactions of pathogens: PI3 and MH (0.01%), RSV and MH (0.01%), PM and MH (0.02%). This was the first study that immunohistochemically demonstrated bacterial and viral antigens in naturally occurring pneumonia in cattle in Nigeria and Ghana.