Transmission of Mycobacterium bovis from experimentally infected ferrets to non-infected ferrets (Mustela furo)

Aims: To demonstrate the transmission of Mycobacterium bovis infection from experimentally infected ferrets (Mustela furo) to non-infected ferrets in a laboratory setting, using three different isotypes of M. bovis and to obs erve ferret behaviour that might be implicated in disease transmission. Methods: Three female ferrets, each experimentally infected with a unique s train of M. bovis, were housed together with six female and two male non-in fected ferrets in an isolation facility. Transmission of infection was moni tored clinically, serologically (using an ELISA test), bacteriologically, h istologically, and by isotype analysis of M. bovis isolates using spoligoty ping to determine whether or not transmission of each strain occurred. Ferr et behaviour was observed using a time-lapse video recorder. Results: Transmission of M. bovis infection was confirmed in two male and f our female ferrets. Isotype analysis showed that of the experimentally infe cted females, one did not infect any other ferret, another transmitted M. b ovis to one ferret before it died prematurely 49 days post-infection, and t he third, which was cannibalised, appears to have transmitted M. bovis to b oth males and three females. However, two of these latter three females had died before the event of cannibalism took place. One female was infected w ith two strains. Several behavioural interactions were observed that could have resulted in M. bovis transmission, including den sharing, sniffing of orifices and faeces, cannibalism and aggressive breeding behaviour. Conclusions: Horizontal transmission of M. bovis infection was demonstrated in ferrets under experimental housing conditions. Routes of transmission m ay involve cannibalism and factors such as den sharing, playing, fighting, mating, and sniffing of faeces.