Habitat fragmentation, climate change, poaching, human-wildlife conflicts, and infectious diseases are the main threats to biodiversity conservation. They alter host-pathogen dynamics, reduce viable conservation areas, and promote genetic isolation, resulting in physiological stress among animal populations. Moreover, increased proximity between domestic and wild animals further facilitates disease spillovers, exposing naive host species and ecosystems to new pathogens. Of the more than 200 known zoonotic diseases, approximately 60% originate from animals, contributing significantly to the global infectious disease burden. Here, we describe the development of an innovative non-invasive approach for biological sampling that has been validated in mice and shelter cats. Our device consists of a disposable plastic cassette that, through odor attractants, lures animals to lick a filter paper. This saliva collection approach allowed for the detection of RNA viruses by RTqPCR and third-generation sequencing. RTqPCR oral swab and licked paper results showed that both methods significantly predicted serological status. Our sequencing results revealed the richness of the gene space, demonstrating the potential of this device for discovering rare or unknown species circulating in the saliva donor, enabling this player to be recognized as an environmental sentinel. This study demonstrates the feasibility of deploying this device in sheltered/captive animal settings as well as under laboratory simulations of different environments, providing necessary foundations for future field applications. Our methodology holds great potential for monitoring zoonotic pathogens in both captive and free-ranging animals, to even possibly allow proactive mitigation measures prior to spillover, without interfering with natural animal behaviour and social structures.