Emerging diseases are rapidly becoming a global conservation issue, and traditional approaches to understanding transmission among in-situ populations often involved investigating hosts in the context of a single pathogen. Yet it is clear now that understanding disease dynamics within ecological frameworks must address hosts as simultaneously infected with multiple organisms. Helminths are among the most common parasites of vertebrates, yet their impact on host populations are underappreciated due to their typical subclinical effects. Conversely, helminths may indirectly play a role in the spread of other virulent pathogens. Yet before these interactions are investigated, the consequences of parasitism in non-native and polymorphic organisms must be addressed. This study examines free-ranging urban Rock Pigeons naturally exposed to gastrointestinal helminths, blood parasites and avian paramyxovirus-1 virus (APMV-1) in Atlanta, Georgia to examine implications of parasite enemy release, melanism and body condition as drivers of pathogen susceptibility.