Beneath the Feathers: Hidden Burden of Serratospiculum and Other Endoparasites in Falcons Raised in Captivity in Serbia

Parasitic infections represent an important health challenge in falcons (Falconidae), where they may negatively influence survival, reproduction, and performance. This study is the first investigation in Serbia assessing the prevalence and diversity of endoparasites in captive falcons, with special emphasis on Serratospiculum spp. A total of 145 live birds (hybrid falcon, Falco peregrinus, F. cherrug, F. rusticolus) and 1 dead individual were examined. Diagnostic procedures included necropsy, coprological analysis, and molecular detection. Endoparasites were confirmed in 55.2% of fecal samples. The most frequent were Caryospora spp. (41.4%), followed by Porrocaecum spp. (18.6%), Capillaria spp. (3.4%), and Serratospiculum spp. (2.8%). Statistically significant differences were observed between sexes, locations, and preventive health management. Falcons kept under preventive measures showed a markedly lower prevalence compared with those lacking such care. These findings highlight the persistent occurrence of endoparasites in Serbian falcons and underscore the importance of preventive programs. Regular deworming, strict hygiene, and vector control represent essential strategies for minimizing infections, particularly of Serratospiculum spp., which poses a serious respiratory health threat.