Abstract
BACKGROUND: Currently, six species of Callithrix are frequently observed in anthropized and degraded environments in different regions of Brazil. This occupation favors interactions with humans and increases the risk of infection by parasites with zoonotic potential. This study assessed the occurrence of enteroparasites in free-ranging Callithrix spp. from different municipalities in Paraná state, Brazil, from a One Health approach. METHODS: Faecal samples of 37 specimens of C. penicillata, C. jacchus, and hybrid species were analyzed. RESULTS: The most frequent parasite forms observed included helminth eggs (Ascaridida, Rhabditida, Trichostrongylidae), and protozoan oocysts and cysts (Coccidia, Diplomonadida). Clinical evaluations of the animals indicated musculoskeletal abnormalities, dental changes, skin injuries, gastrointestinal signs, and low body weight. CONCLUSIONS: The presence of parasites with zoonotic potential highlights the need for ongoing surveillance of marmoset populations, underscoring the importance of maintaining a balanced relationship among the environment, humans, and animals within the One Health approach.