PATHOMORPHOLOGICAL CHANGES ON CONCHAE OF PIGLETS EXPERIMENTALLY INFECTED WITH BORDETELLA-BRONCHISEPTICA

Atrophic rhinitis was provoked in two or three-day old piglets by intr anasal application of a culture of a virulent strain of B. bronchisept ica. B. bronchiseptica could be isolated from the lungs until day 60, from the trachea until day 75 and from the conchae until day 120. The causative agent could be isolated from the ethmoid sinus until day 165 of the infection. Clinical symptoms were evident on day 5 after infec tion and were noticeable until day 60. Macroscopic changes on conchae appeared as hyperemia, the presence of haemorhagic content and differe nt degrees of conchae atrophy (1-5) with deformation of the nasal sept um. Atrophic changes were evident on day 23 of the infection and could be noticed until the end of the investigation. Changes on the lungs o f animals that died and sacrificed animals appeared as fibrous pneumon ia on the apical and cardiac lobes of both lungs. Pathohistological ch anges which are characteristic for atrophic rhinitis were found in all infected animals from day 12 of the infection until the end of the ex perimental period. The type of changes depended on the infection stadi um and they appeared as epithelial proliferation, disappearance of cup -shaped cells, cell losses and destruction of bone trabeculae.