Figure 1. Schematic representing the possible age-specific force-of-infection for transmission of Bordetella bronchiseptica infection to New Zealand White rabbits in a commercial rabbitry.

Possible routes of transmission include (a) the pseudo-vertical route from mother to new born offspring until the age of weaning (∼4 to 5 weeks), (b) horizontally between siblings when re-housed at age of independence (from 4 to 5 weeks until 5 to 6 months of age), (c) horizontally at time of breeding (from 5 to 6 months onwards) and (d) transmission from birth due to environmental contamination.