Gastrointestinal protozoan and helminth parasite infections in captive chameleons in Germany

Within lizards, chameleons (family Chamaeleonidae) represent a distinctive and highly specialized clade of insectivorous reptiles. Chameleons have become more popular as reptile pets in recent years worldwide, due to their feasible husbandry and attractiveness. To date, not only reptile pet numbers but also health-compromising endoparasite infections are rising. In the current study, we analyzed a total of 670 faecal samples of 25 different chameleon species kept as pet animals all over Germany. In total, 223 animals (33%) were found to harbor gastrointestinal parasites. In total, 10 different parasite taxa were diagnosed in chameleon faecal samples. The most prevalent parasite stages were oxyurid eggs (14.1%), followed by coccidia oocysts (7.8%) (e.g. Isospora jaracimrmani, Isospora spp., Choleoeimeria spp., Eimeria spp.), flagellated protozoan trophozoites (6.3%) (e.g. Leptomonas spp., Tritrichomonas spp., Proteromonas spp.), heterakid eggs (3.6%), thin-shelled nematode eggs (3.6%), digenean trematode eggs (0.6%), pentastomid eggs (0.3%), ascarid eggs (0.2%), Entamoeba spp. cysts (0.2%) and physalopteroid eggs (0.2%). Among current chameleon species, veiled chameleons (Chamaleo calyptratus) showed a significantly higher prevalence of oxyurid infections (64%) than other chameleon species. Co-infections were diagnosed in 9.8% (22/223) of faecal samples. When performing necropsies, 19/31 chameleons showed parasite-induced pathologies based on histopathological examinations, including one animal being infected with 4 parasite species (Leptomonas spp., Tritrichomonas spp., Foleyella furcata and Hexametra angusticaecoides), thereby most likely impacting animal’s welfare.