To better understand the role of pigs in transmission of zoonotic diseases it was first necessary to first learn more about the ecology of domestic pigs kept under typical free-range conditions in western Kenya. Little is known about the behavior of pigs kept under these conditions, yet we could draw upon a wealth of knowledge from those studying the ecology of wild mammals to design our work.

This project used GPS technology (savannah tracking) to track the movements of 10 randomly selected pigs. This allowed us to establish their typical ‘home range’, the distance they walked over the course of a week and the environmental features they interacted with. We also looked at the diseases, zoonotic and non-zoonotic, that they suffered from so that we could start to understand the link between the spatial ecology of these animals and their disease burden.

The results of this small study are discussed in a paper appearing in BMC veterinary research (http://www.biomedcentral.com/1746-6148/9/46) but briefly we were able to establish that pigs kept in free-range systems travel great distances in their search for food (over 4km a day) and their home range, of 10,000m² is bigger than the typical homestead in western Kenya. Both of these factors mean that free-range pigs scavenging for food are at a high risk of exposure to disease from outside their homestead of origin which, as you can imagine, is a major biosecurity risk.

The data arising from this study has also been utilized by our collaborators from the University of Guelph (http://ovc.uoguelph.ca/population-medicine/faculty/cate-dewey) who are working on improving pig production in western Kenya through the formulation of appropriate and accessible pig feeds. A collaborative paper has been submitted to the Journal of Tropical Health & Production.

By Dr. Lian Thomas