The role of wild canids and felids in spreading parasites to dogs and cats in Europe Part I: Protozoa and tick-borne agents

Over the last few decades, the world has witnessed radical changes in climate, landscape, and ecosystems.These events, together with other factors such as increasing illegal wildlife trade and changing humanbehaviour towards wildlife, are resulting into thinning boundaries between wild canids and felids andtheir domestic counterparts. As a consequence, the epidemiology of diseases caused by a number ofinfectious agents is undergoing profound readjustements, as pathogens adapt to new hosts and environ-ments. Therefore, there is a risk for diseases of wildlife to spread to domestic carnivores and vice versa,and for zoonotic agents to emerge or re-emerge in human populations. Hence, the identification of thehazards arising from the co-habitation of these species is critical in order to plan and develop adequatecontrol strategies against these pathogens. In the first of this two-part article, we review the role thatwild canids and felids may play in the transmission of protozoa and arthropod-borne agents to dogs andcats in Europe, and provide an account of how current and future progress in our understanding of theecology and epidemiology of parasites, as well as of host-parasite interactions, can assist efforts aimedat controlling parasite transmission.© 2015 Elsevier B.V. All rights reserved.1. From wildlife management to public health concernsThere is an increased awareness of the global effects of severalaspects of human politics (e.g. industrialization, urbanization, frag-mentation of the environment, land use, recycling in urban settings,lack of political will) on the ‘health’ of the planet, and on the alter-ations that humankind is causing on the precarious balances of theecosystems. The resilience of ecosystems is being challenged bythe thinning boundaries between domestic and wild animals, ulti-mately resulting in a redistribution of infective agents (Thompsonet al., 2010; Colwell et al., 2011; Tompkins et al., 2015). These∗Corresponding author. Tel.: +39 080 4679839; fax: +39 080 4679837.E-mail address: domenico.otranto@uniba.it (D. Otranto).changing scenarios are not only of concern to animal and envi-ronmental conservation, but they are likely to become an issueof public health relevance, especially considering their effects onthe epidemiology of some infectious diseases (Fig. 1). For instance,parasites affecting both domestic and wild carnivores may circu-late between and among sympatric populations of animals, thusfacilitating potential spill-overs of the infections to humans (Polley,2005). Indeed, wild and domestic carnivores are considered the firstsource of human infections with zoonotic agents, which include, indescending order, viruses, protozoa, bacteria, and fungi (Cleavelandet al., 2001). In particular, while until recently domestic animalswere mostly blamed for the transmission of zoonoses to humans(e.g. livestock through consumption of meat and dairy products),the emergence or re-emergence of zoonotic infections have stim-ulated studies on the role that wild birds and mammals, includinghttp://dx.doi.org/10.1016/j.vetpar.2015.04.0220304-4017/© 2015 Elsevier B.V. All rights reserved.