Gut microbiota homeostasis is important for host health and well-being; however, drugs may affect the composition and function of the gut microbiota. Red-crowned cranes are a vulnerable species. Treatment of red-crowned cranes with avian influenza vaccines and anthelmintics has played pivotal roles in therapeutic management in zoos. To investigate the changes in the diversity and composition of gut microbiota after the avian influenza vaccine and anthelmintic treatment, we used 16S rRNA sequencing to obtain and compare the bacterial community composition before and after the treatment. The alpha diversity of the gut microbiota of red-crowned cranes decreased on the day of the treatment and then fluctuated over time. The composition of gut microbiota tended to be similar in the short term after the treatment, as supported by the beta diversity hierarchical cluster analysis. Only 3, 8, and 72 operational taxonomic units (OTUs) of the three individuals were shared among the five groups before and after treatment. The relative abundance of Firmicutes significantly increased to 99.04% ± 0.28% on the day of the treatment, in which the relative abundance of Lactobacillus was 93.33% ± 5.85%. KEGG pathways analysis indicated that the main function of the gut microbiota is involved in metabolism, and the present study indicates that the gut microbiota of red-crowned cranes is resilient to the avian influenza vaccine and anthelmintic, even disordered in the short term, and could recover over time. More individual experimentation and functional potential in metabolism are needed in the future to support animal disease control and optimal management in the zoo.

The red-crowned crane (Grus japonensis) is a critically endangered species. Three-dimensional–printed prosthetic beaks made of titanium alloy and polyether ether ketone (PEEK) were used to repair the beak of a red-crowned crane that had a complete fracture of the anterior maxillary bone and rhinotheca. The physical properties and stability of the prostheses and changes in the crane's behaviors after application of either beak were evaluated. The titanium alloy and PEEK prosthetic beaks weighed 30.81 g and 5.9 g, respectively. Scanning electron microscopy showed differences in microstructure between the 2 materials and the true beak; the true beak was softer than both materials from which the prostheses were made. The titanium beak frequently detached, and the residual natural beak showed significant cuticle softening with this prosthetic beak. The titanium beak detached within an approximately 3-month period after placement, whereas the PEEK prosthetic beak has remained secure for 2 years. Moreover, the crane's foraging times (P < .01) and grooming times (P < .05) with the titanium alloy false beak were lower than the normal, red-crowned crane. With the PEEK beak, no detachment or cuticle softening occurred, and foraging and grooming behaviors were evaluated by the investigators as natural (P > .05). Based on the results of this clinical case, the PEEK prosthetic beak was found to be superior to the titanium alloy prosthetic beak in color, weight, firmness, and postoperative effects.