Estimating the extent of disease transmission among and within species is a prerequisite for effective control of undesirable diseases such as bovine Tb (Caley and Hone 2004). In the northern South Island high country (NSIHC), control and eventual eradication of bovine Tb poses some major challenges. In this region, three species (possums (Trichosurus vulpecular), feral pigs (Sus scrofa), and ferrets (Mustela furo)) are frequently infected and play varying roles in both the persistence and spread of the disease in a vast and largely unforested landscape. Understanding the routes and frequencies of Tb transmission between these species is likely to be crucial in designing the most efficient and effective programmes for disease management in this area (Byrom 2004; Nugent et al. 2003; Yockney and Nugent 2003).
Ferrets are generally regarded as a spillover host of bovine Tb in New Zealand (Byrom 2001). However in some areas, rapid expansion of Tb-endemic areas has been linked to long-distance movements by ferrets and subsequent transmission of infection to cattle and deer, and/or spread of infection to other wild animals (including other ferrets) at new locations (Livingstone 1996). Furthermore, observed behaviour of ferrets and other wildlife species at ferret carcasses suggests that transmission of Tb could occur through scavenging of infected material (Ragg et al. 2000). However, the frequency, nature and duration of such interactions with ferret carcasses suggests that transmission of Tb could occur through scavenging of infected material (Ragg et al. 2000). However, the frequency, nature and duration of such interactions with ferret carcasses remain largely unquantified.
The aims of this study were twofold. First, to quantify the potential for young ferrets (nominally infected with Tb) to transport the disease during dispersal in the NSIHC. Second, to determine which species of wildlife are most likely to encounter and scavenge on ferret carcasses in the NSIHC, and so characterise the likely fate of Tb present in infected carcasses (and potential routes of transmission back to other wildlife species). This information is critical in assessing whether ferrets play an important role in the persistence and spread of Tb in the landscape, and therefore in determining how much emphasis should be placed on ferret control in vector management programmes in New Zealand.
|Reference type||Conference or Workshop Proceedings|
|Author||Byrom, A., Nugent, G. and Yockney, I|
|Secondary title||13th Australasian Vertebrate Pest Conference|
|Place published||Wellington, NZ|