Conclusion
Interactions among parasites in naturally coinfected animals are well-recorded. Incorporating multiple guilds of parasites in a comprehensive network has, however, been less commonly reported, particularly in model species. Every parasite surveyed in this wild host population was implicated in an association with at least one other parasite, with multiple cross-guild interactions observed. Interactions which may explain many of these associations are potentially immune-mediated, as most of the species pairs exhibiting associations exist within different niches. C. hepaticum and T. muris impart well-characterised changes to immune state in infection models which may be evident here. While potential pathogens such as viruses are not included in this study, we have demonstrated the importance of accounting for coinfection when studying parasitic infection in wild populations, and the prevalence of cross-guild associations which may not be always accounted for during studies of natural infections. This point is highlighted by the prominence of associations between C. hepaticum, an often overlooked infection in wild rodent populations, and ectoparasites, bacteria, protozoa and helminths within other niches. The associations reported here are based on cross-sectional data; this work would be greatly improved with the addition of longitudinal data, to determine causality in associations, examine the significance of order of infection, and obtain a clearer picture of the mechanisms underlying coinfection dynamics.