**The role of Bordetella bronchiseptica in URTD of cats**


Bacterial colonisation of the nasal cavity occurs relatively easily.

Bordetella species interact with their mammalian hosts primarily, and perhaps exclusively, at respiratory surfaces. Bacterial colonisation of the nasal cavity occurs relatively easily. Establishment of infection in the trachea, however, requires that bacteria are able to resist or overcome the clearance action of the mucociliary escalator as well as the killing effects of protecting factors.

Bordetella bronchiseptica is able to induce respiratory disease in the absence of other pathogens. This is supported by the field study of Binns et al 1999) which demonstrated no significant association between the isolation of Bordetella bronchiseptica (Bb) and the isolation of other respiratory viruses.

Bb can act as a primary pathogen. However, it is highly likely that in many circumstances other factors are involved in the development of upper respiratory tract disease (URTD) including stress and concurrent infection with respiratory viruses. Bb may also act as a secondary pathogen, particularly in cases of URTD which progress to more lethal bronchopneumonia.