4 research outputs found
Pathogens, patterns of pneumonia, and epidemiologic risk factors associated with respiratory disease in recently weaned cattle in Ireland
peer-reviewedWe examined the pathogens, morphologic patterns, and risk factors associated with bovine respiratory disease
(BRD) in 136 recently weaned cattle (“weanlings”), 6–12 mo of age, that were submitted for postmortem examination to
regional veterinary laboratories in Ireland. A standardized sampling protocol included routine microbiologic investigations
as well as polymerase chain reaction and immunohistochemistry. Lungs with histologic lesions were categorized into 1 of 5
morphologic patterns of pneumonia. Fibrinosuppurative bronchopneumonia (49%) and interstitial pneumonia (48%) were
the morphologic patterns recorded most frequently. The various morphologic patterns of pulmonary lesions suggest the
involvement of variable combinations of initiating and compounding infectious agents that hindered any simple classification
of the etiopathogenesis of the pneumonias. Dual infections were detected in 58% of lungs, with Mannheimia haemolytica and
Histophilus somni most frequently recorded in concert. M. haemolytica (43%) was the most frequently detected respiratory
pathogen; H. somni was also shown to be frequently implicated in pneumonia in this age group of cattle. Bovine parainfluenza
virus 3 (BPIV-3) and Bovine respiratory syncytial virus (16% each) were the viral agents detected most frequently. Potential
respiratory pathogens (particularly Pasteurella multocida, BPIV-3, and H. somni) were frequently detected (64%) in lungs
that had neither gross nor histologic pulmonary lesions, raising questions regarding their role in the pathogenesis of BRD.
The breadth of respiratory pathogens detected in bovine lungs by various detection methods highlights the diagnostic value of
parallel analyses in respiratory disease postmortem investigation
The number and relative frequency of detection of bacterial and viral pathogens in the paranasal sinuses (caudal frontal, rostral medial frontal, rostral lateral frontal and maxillary sinuses) of clinically normal cattle (n = 99) and of cattle submitted for Post-Mortem Examination (PME) (n = 34).
<p>Polymerase chain reaction (PCR) analyses were performed for BRSV (n = 133), BPIV-3 (n = 133), <i>M</i>.<i>haemolytica</i> (n = 56), <i>P</i>. <i>multocida</i> (n = 56), <i>H</i>.<i>somni</i> (n = 67) and <i>M</i>. <i>bovis</i> (n = 67).</p
The relative frequency of detection of antibodies to BPIV-3 and BRSV in serum and the relative frequency of detection of selected viral and bacterial BRD-causing pathogens in the trachea and lungs of the study population.
<p>The relative frequency of detection of antibodies to BPIV-3 and BRSV in serum and the relative frequency of detection of selected viral and bacterial BRD-causing pathogens in the trachea and lungs of the study population.</p